Upload 101 files

app.py

@@ -1084,6 +1084,12 @@ def _inline_math_to_unicode(text: str) -> str:
     return re.sub(r'\$([^\$]+)\$', _convert, text)
 
 
+#: Tokens the formula pattern below matches but which are not chemical formulas:
+#: retrieval-channel and method names shown in the evidence list. Compared
+#: case-insensitively.
+_NON_FORMULA_TOKENS = frozenset({"BGE-M3", "BM25"})
+
+
 def _normalize_report_formula_display(text: str) -> str:
     if not text:
         return ""
@@ -1103,6 +1109,11 @@ def _normalize_report_formula_display(text: str) -> str:
         token = match.group(0)
         if len(token) < 2:
             return token
+        # Retrieval-channel and method names are uppercase-plus-digits, which is
+        # exactly the shape of a formula: without this guard "BGE-M3" renders as
+        # "BGE-M₃" and "BM25" as "BM₂₅" in the evidence list.
+        if token.upper() in _NON_FORMULA_TOKENS:
+            return token
         prefix = ""
         lowered = token.lower()
         for phase_prefix, symbol in (("alpha-", "α-"), ("beta-", "β-")):
@@ -2382,7 +2393,24 @@ def _render_report_html(report_item):
     if scope_note:
         md_parts.append("### Evidence Scope\n\n> " + scope_note)
 
-    retrieved_evidence_lines = []
+    # Grouped by reaction step, not by reference. Listing each reference
+    # separately repeated one conclusion once per supporting paper -- five
+    # identical "As4S4 -> p-As4S4: direct" lines in one report -- which buried
+    # the question a reader actually has: is this step supported, and by whom.
+    # Each step is stated once, with the references and channels that back it.
+    def _add_support(bucket, key, reference_index, channels):
+        entry = bucket.setdefault(
+            key, {"refs": [], "channels": []}
+        )
+        if reference_index not in entry["refs"]:
+            entry["refs"].append(reference_index)
+        for channel in channels:
+            if channel not in entry["channels"]:
+                entry["channels"].append(channel)
+
+    step_support = {}
+    endpoint_support = {}
+    unclassified_support = {}
     for index, block in enumerate(evidence_blocks, 1):
         if not isinstance(block, dict):
             continue
@@ -2391,47 +2419,65 @@ def _render_report_html(report_item):
         )
         if not snippet:
             continue
-        status = str(block.get("evidence_status") or "unclassified").replace("_", " ")
-        # Human-readable classification for researchers rather than a developer
-        # log line: name the actual reaction (reactant -> product) each reference
-        # supports, spell the verdict as a phrase, and list the retrieval
-        # channels on their own line with display names (bge_m3 -> BGE-M3).
-        edge_lines = []
-        endpoint_support = False
-        for match in block.get("edge_matches") or []:
-            if not isinstance(match, dict):
-                continue
-            if match.get("evidence_scope") == "pathway_endpoint":
-                endpoint_support = True
-                continue
-            reactant = to_unicode_subscript(str(match.get("reactant") or ""))
-            product = to_unicode_subscript(str(match.get("product") or ""))
-            verdict = str(match.get("verdict") or "unclassified").replace("_", " ")
-            phrase = "direct literature support" if verdict == "direct" else f"{verdict} support"
-            edge_lines.append(f"{reactant} → {product}: {phrase}" if reactant and product else phrase)
-        # The same edge can match in several snippets of one reference; show each
-        # classification once (it was being repeated).
-        edge_lines = list(dict.fromkeys(edge_lines)) or [status]
-        detail_lines = []
-        if endpoint_support:
-            detail_lines.append("Additional support: pathway endpoints")
-        origins = list(dict.fromkeys(
+        channels = list(dict.fromkeys(
             _RETRIEVAL_CHANNEL_LABELS.get(name, name)
             for item in block.get("snippets") or []
             if isinstance(item, dict) and item.get("retrieval_origin")
             for name in [str(item.get("retrieval_origin") or "").replace("_", " ")]
         ))
-        if origins:
-            detail_lines.append("Retrieval channels: " + "; ".join(origins))
-        # The classification stays; the quoted passage does not. It tells a reader
-        # which reaction a reference supports and how it was found. The passage
-        # behind it runs to 900 characters, several per report, and the exported
-        # PDF already carries every one of them under "Evidence Assessment".
-        block_md = f"[{index}] **{edge_lines[0]}**"
-        tail = edge_lines[1:] + detail_lines
-        if tail:
-            block_md += "  \n" + "  \n".join(tail)
-        retrieved_evidence_lines.append(block_md)
+        matches = [m for m in (block.get("edge_matches") or []) if isinstance(m, dict)]
+        if not matches:
+            status = str(block.get("evidence_status") or "unclassified").replace("_", " ")
+            _add_support(unclassified_support, status, index, channels)
+            continue
+        for match in matches:
+            verdict = str(match.get("verdict") or "unclassified").replace("_", " ")
+            reactant = to_unicode_subscript(str(match.get("reactant") or ""))
+            product = to_unicode_subscript(str(match.get("product") or ""))
+            if match.get("evidence_scope") == "pathway_endpoint":
+                _add_support(
+                    endpoint_support, (reactant, product, verdict), index, channels
+                )
+                continue
+            try:
+                order = int(match.get("edge_index") or 0)
+            except (TypeError, ValueError):
+                order = 0
+            _add_support(
+                step_support, (order, reactant, product, verdict), index, channels
+            )
+
+    def _support_detail(entry):
+        lines = ["Sources: " + " ".join(f"[{n}]" for n in sorted(entry["refs"]))]
+        if entry["channels"]:
+            lines.append("Retrieval: " + "; ".join(entry["channels"]))
+        return lines
+
+    retrieved_evidence_lines = []
+    for (_order, reactant, product, verdict) in sorted(step_support):
+        entry = step_support[(_order, reactant, product, verdict)]
+        phrase = (
+            "direct literature support" if verdict == "direct" else f"{verdict} support"
+        )
+        heading = f"{reactant} → {product} — {phrase}" if reactant and product else phrase
+        retrieved_evidence_lines.append(
+            f"**{heading}**  \n" + "  \n".join(_support_detail(entry))
+        )
+    for (reactant, product, verdict) in sorted(endpoint_support):
+        entry = endpoint_support[(reactant, product, verdict)]
+        label = f"Overall {reactant} → {product}" if reactant and product else "Overall pathway"
+        phrase = (
+            "pathway-endpoint support" if verdict == "direct"
+            else f"pathway-endpoint {verdict} support"
+        )
+        retrieved_evidence_lines.append(
+            f"**{label} — {phrase}**  \n" + "  \n".join(_support_detail(entry))
+        )
+    for status in sorted(unclassified_support):
+        entry = unclassified_support[status]
+        retrieved_evidence_lines.append(
+            f"**{status}**  \n" + "  \n".join(_support_detail(entry))
+        )
     if retrieved_evidence_lines:
         md_parts.append(
             "### Retrieved Literature Evidence\n\n"

chroma.sqlite3

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d20c82236b019a159ad419b36c6f3e0f490437cac3c43174b64aa499c35019cf
+oid sha256:71a2ca162a767171d63c8a25878a4a4a8b36d9bf9d43cd5bb5b3d4c7c5f43327
 size 26365952

precompute_rag_cache.py

@@ -0,0 +1,93 @@
+"""Offline warm-up of the pathway report cache.
+
+Retrieval and evidence gating are deterministic in (path, corpus), but a full
+run costs minutes of CPU per path. This script computes every pathway report
+once, offline, so the running app serves them from cache instead of recomputing
+an identical answer on each request.
+
+Run it after the knowledge base changes (the cache key carries a corpus
+fingerprint, so stale entries are ignored automatically rather than served).
+
+    python precompute_rag_cache.py            # all reachable targets
+    python precompute_rag_cache.py As2O3 PbO  # only these targets
+
+Interrupting is safe: finished paths stay cached, so a re-run resumes.
+"""
+from __future__ import annotations
+
+import os
+import sys
+import time
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+# Some network node names carry zero-width characters, and the tracer prints the
+# target name on a miss. On a GBK console that print raises UnicodeEncodeError
+# and aborts the run, so force UTF-8 output and never fail on an odd glyph.
+for _stream in (sys.stdout, sys.stderr):
+    try:
+        _stream.reconfigure(encoding="utf-8", errors="replace")
+    except (AttributeError, ValueError):
+        pass
+
+
+def main(argv: list[str]) -> int:
+    from search_subgraph import CRNTracer, GRAPHML_PATH
+    from tracernet.crn import pathways as crn_pathways
+    from tracernet.crn.repository import CRNRepository
+    from rag_module import RAGService
+
+    project = os.path.dirname(os.path.abspath(__file__))
+    repository = CRNRepository.discover([project])
+    tracer = CRNTracer(GRAPHML_PATH, crn_repository=repository)
+    graph = tracer.G
+    service = RAGService(repository)
+    print(f"[init] graph={graph.number_of_nodes()} nodes, "
+          f"corpus signature={service._report_cache_signature()}", flush=True)
+
+    targets = argv or sorted(graph.nodes())
+    print(f"[plan] tracing {len(targets)} candidate targets ...", flush=True)
+
+    # Collect unique paths across every target. The same path is reachable from
+    # several targets, and computing it twice would cost minutes for nothing.
+    jobs: dict[str, tuple[str, object]] = {}
+    for target in targets:
+        try:
+            _resolved, _graph, _report, all_paths = crn_pathways.trace_material_pathways(
+                tracer, graph, target, max_depth=10, limit=100
+            )
+        except Exception as error:  # a target with no upstream path is normal
+            print(f"[trace] {target}: skipped ({type(error).__name__})", flush=True)
+            continue
+        for info in all_paths or []:
+            path_str = info.get("path_str")
+            if path_str and path_str not in jobs:
+                jobs[path_str] = (info.get("source"), info.get("full_path"))
+    print(f"[plan] {len(jobs)} unique pathways to warm", flush=True)
+
+    started = time.time()
+    done = 0
+    for index, (path_str, (source, full_path)) in enumerate(jobs.items(), 1):
+        step = time.time()
+        try:
+            # Evidence only: the narrative is generated per request, so warming
+            # it here would be discarded work -- and with an API key configured
+            # it would spend one LLM call per path for nothing.
+            service.cached_path_evidence(source, path_str, full_path)
+            done += 1
+            status = "ok"
+        except Exception as error:
+            status = f"FAILED {type(error).__name__}: {error}"
+        elapsed = time.time() - step
+        total = time.time() - started
+        print(f"[{index}/{len(jobs)}] {elapsed:6.1f}s  total {total/60:5.1f}m  "
+              f"{status}  {path_str[:90]}", flush=True)
+
+    print(f"[done] warmed {done}/{len(jobs)} pathways in "
+          f"{(time.time()-started)/60:.1f} minutes", flush=True)
+    print(f"[done] cache directory: {service._report_cache_dir()}", flush=True)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main(sys.argv[1:]))

rag_module.py

@@ -2631,7 +2631,129 @@ include a "Validation note"; it is added automatically outside your paragraph.
         """
         return list(candidates)[:max(0, int(output_top_k))]
 
+    def _report_cache_dir(self):
+        return os.getenv("RAG_REPORT_CACHE_DIR") or os.path.join(
+            os.path.dirname(os.path.abspath(__file__)), "rag_report_cache"
+        )
+
+    def _report_cache_signature(self):
+        """Corpus fingerprint, so a rebuilt knowledge base invalidates the cache.
+
+        A cached report is only valid for the corpus it was computed from. The
+        document count changes whenever papers are added or removed, which is
+        exactly when the stored evidence stops being reproducible.
+        """
+        count = self.collection_count
+        if count is None:
+            try:
+                collection = getattr(self.vector_db, "_collection", None) or self.chroma_collection
+                count = collection.count() if collection is not None else -1
+            except Exception:
+                count = -1
+        return f"docs={count}"
+
+    def _report_cache_key(self, root_material, path_str):
+        import hashlib
+
+        payload = "|".join([
+            str(root_material or ""),
+            str(path_str or ""),
+            self._report_cache_signature(),
+        ])
+        return hashlib.sha1(payload.encode("utf-8")).hexdigest()
+
     def generate_report_for_path(self, root_material, path_str, full_path=None):
+        """Return the pathway report, reusing cached retrieval evidence.
+
+        Retrieval and evidence gating are deterministic in (path, corpus) yet cost
+        minutes of CPU, so recomputing them per request spends that time
+        reproducing an identical answer; they are cached on disk, keyed by path
+        and corpus fingerprint, so a changed knowledge base recomputes rather
+        than serving stale evidence. The narrative is deliberately NOT cached --
+        it is regenerated on every call so the wording is never frozen, which
+        costs seconds rather than minutes. Set RAG_REPORT_CACHE=0 to bypass.
+        """
+        cache_enabled = os.getenv("RAG_REPORT_CACHE", "1").strip().lower() not in (
+            "0", "false", "no"
+        )
+        evidence = self.cached_path_evidence(root_material, path_str, full_path)
+        return self._narrate_path_report(
+            evidence, root_material, path_str, full_path
+        )
+
+    def cached_path_evidence(self, root_material, path_str, full_path=None):
+        """Retrieval evidence for one path, computed once and cached on disk.
+
+        Exposed separately so the offline warm-up can fill the cache without
+        generating a narrative: narration is a per-request concern and, with an
+        API key configured, warming 88 paths through the full report path would
+        spend 88 LLM calls on text that is thrown away.
+        """
+        cache_enabled = os.getenv("RAG_REPORT_CACHE", "1").strip().lower() not in (
+            "0", "false", "no"
+        )
+        cache_file = None
+        evidence = None
+        if cache_enabled:
+            cache_file = os.path.join(
+                self._report_cache_dir(),
+                f"{self._report_cache_key(root_material, path_str)}.json",
+            )
+            try:
+                if os.path.isfile(cache_file):
+                    with open(cache_file, "r", encoding="utf-8") as handle:
+                        cached = json.load(handle)
+                    stored = cached.get("evidence")
+                    # Every field the narrative half reads must be present, or a
+                    # cache written by an older layout would fail mid-report.
+                    if isinstance(stored, dict) and all(
+                        key in stored
+                        for key in (
+                            "context_str", "ref_list", "ref_snippets",
+                            "related_context", "retrieval_trace",
+                        )
+                    ):
+                        evidence = stored
+                        logger.info(
+                            "[RAG][CACHE] evidence hit path=%s", str(path_str)[:120]
+                        )
+            except (OSError, ValueError):
+                logger.warning(
+                    "[RAG][CACHE] unreadable entry ignored: %s", cache_file
+                )
+
+        if evidence is None:
+            evidence = self._retrieve_path_evidence(
+                root_material, path_str, full_path
+            )
+            if cache_enabled and cache_file:
+                try:
+                    os.makedirs(os.path.dirname(cache_file), exist_ok=True)
+                    # Write to a temporary file first so a crash mid-write cannot
+                    # leave a truncated entry that later reads as valid evidence.
+                    temporary = cache_file + ".tmp"
+                    with open(temporary, "w", encoding="utf-8") as handle:
+                        json.dump(
+                            {
+                                "root_material": root_material,
+                                "path_str": path_str,
+                                "signature": self._report_cache_signature(),
+                                "evidence": evidence,
+                            },
+                            handle,
+                            ensure_ascii=False,
+                            default=str,
+                        )
+                    os.replace(temporary, cache_file)
+                    logger.info(
+                        "[RAG][CACHE] stored evidence path=%s", str(path_str)[:120]
+                    )
+                except (OSError, TypeError, ValueError):
+                    logger.warning("[RAG][CACHE] could not store %s", cache_file)
+
+        return evidence
+
+    def _retrieve_path_evidence(self, root_material, path_str, full_path=None):
         edges = parse_path(path_str)
         mini_report = {root_material: [path_str]}
         generated_queries = self.query_generator.generate_queries(mini_report)
@@ -3645,6 +3767,30 @@ include a "Validation note"; it is added automatically outside your paragraph.
         if not context_str:
             context_str = "No relevant literature evidence was retrieved from the vector database."
 
+        return {
+            "context_str": context_str,
+            "ref_list": ref_list,
+            "ref_snippets": ref_snippets,
+            "related_context": related_context,
+            "retrieval_trace": retrieval_trace,
+        }
+
+    def _narrate_path_report(
+        self, evidence, root_material, path_str, full_path=None
+    ):
+        """Write the report narrative from already-retrieved evidence.
+
+        Split from retrieval so the expensive, deterministic half can be cached
+        while this half runs fresh on every request. Retrieval and evidence
+        gating depend only on (path, corpus) and cost minutes; the narrative is
+        the one part that should not be frozen in a cache, and it costs seconds.
+        """
+        context_str = evidence["context_str"]
+        ref_list = evidence["ref_list"]
+        ref_snippets = evidence["ref_snippets"]
+        related_context = evidence["related_context"]
+        retrieval_trace = evidence["retrieval_trace"]
+
         safe_context = self._smart_truncate(
             context_str,
             max_chars=int(os.getenv("RAG_CONTEXT_MAX_CHARS", "8000")),

rag_report_cache/0275ae9df3f4d1cca2dfbadbf56a3d029df57b25.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[Uv]--> β-PbO2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nTherefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging.\n\n[1] Evidence classification: edge 1: direct\nLead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.\n\n[1] Evidence classification: edge 1: direct\nTherefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging. However, for the model paint samples, because the XRD pattern of tung oil is a broad amorphous feature peak with no peak indicative of crystalline phases (Figure 2B), tung oil is proved as a noncrystalline material by aligning with the characteristics of amorphous peaks; therefore, the XRD pattern of model paint sample represents the result of minium pigment. As can been seen in Figure 2B, crystal structure of the model paint sample changes obviously during UV aging. Before aging, the crystal structure of the model paint sample agrees well with the standard crystal structure of minium, but the most noticeable peaks of minium at 26.3{}^{\\circ}, 30.7{}^{\\circ}, and 32.1{}^{\\circ} begin to diminish while the peaks at 24.8{}^{\\circ}, 27.4{}^{\\circ}, and 34.3{}^{\\circ} appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment crystallinity under UV aging. The formation of the basic lead carbonate (lead white) gives a chalky surface.\n\n[2] Evidence classification: edge 1: direct\nIn water, the darkening of red lead is induced by light, but when NaHCO3 is added red lead transforms to plattnerite even in darkness.\n\n[2] Evidence classification: edge 1: direct\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\n\n[2] Evidence classification: edge 1: direct\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "ref_list": ["ZHAO Y, WANG J, PAN A, et al. Degradation of red lead pigment in the oil painting during UV aging [J/OL]. Color Research & Application, 2019. DOI: 10.1002/col.22386.", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001."], "ref_snippets": [{"text": "Therefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging.\nLead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.\nTherefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging. However, for the model paint samples, because the XRD pattern of tung oil is a broad amorphous feature peak with no peak indicative of crystalline phases (Figure 2B), tung oil is proved as a noncrystalline material by aligning with the characteristics of amorphous peaks; therefore, the XRD pattern of model paint sample represents the result of minium pigment. As can been seen in Figure 2B, crystal structure of the model paint sample changes obviously during UV aging. Before aging, the crystal structure of the model paint sample agrees well with the standard crystal structure of minium, but the most noticeable peaks of minium at 26.3{}^{\\circ}, 30.7{}^{\\circ}, and 32.1{}^{\\circ} begin to diminish while the peaks at 24.8{}^{\\circ}, 27.4{}^{\\circ}, and 34.3{}^{\\circ} appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment crystallinity under UV aging. The formation of the basic lead carbonate (lead white) gives a chalky surface.", "score": 0.45951032638549805, "snippets": [{"text": "Therefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging.", "score": 0.45951032638549805, "metadata": {"doi": "10.1002/col.22386", "source": "markdown_output/Degradation of red lead pigment in the oil painting during UV aging.md", "ingest_kind": "existing_chroma", "chunk_index": 24, "title": "Degradation of red lead pigment in the oil painting during UV aging", "source_file": "Degradation of red lead pigment in the oil painting during UV aging.md", "journal": "Color Research & Application", "year": "2019", "authors": [{"family": "Zhao", "given": "Yanrui"}, {"family": "Wang", "given": "Jianli"}, {"family": "Pan", "given": "Aizhao"}, {"family": "He", "given": "Ling"}, {"family": "Simon", "given": "Stefan"}], "volume": "44", "issue": "5", "pages": "790-797", "url": "https://doi.org/10.1002/col.22386"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Therefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "beta-PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Lead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.", "score": 0.46735185384750366, "metadata": {"source_file": "Degradation of red lead pigment in the oil painting during UV aging.md", "title": "Degradation of red lead pigment in the oil painting during UV aging", "doi": "10.1002/col.22386", "ingest_kind": "existing_chroma", "chunk_index": 35, "journal": "Color Research & Application", "year": "2019", "source": "markdown_output/Degradation of red lead pigment in the oil painting during UV aging.md", "authors": [{"family": "Zhao", "given": "Yanrui"}, {"family": "Wang", "given": "Jianli"}, {"family": "Pan", "given": "Aizhao"}, {"family": "He", "given": "Ling"}, {"family": "Simon", "given": "Stefan"}], "volume": "44", "issue": "5", "pages": "790-797", "url": "https://doi.org/10.1002/col.22386"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "resolver", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Lead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "beta-PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Therefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging. However, for the model paint samples, because the XRD pattern of tung oil is a broad amorphous feature peak with no peak indicative of crystalline phases (Figure 2B), tung oil is proved as a noncrystalline material by aligning with the characteristics of amorphous peaks; therefore, the XRD pattern of model paint sample represents the result of minium pigment. As can been seen in Figure 2B, crystal structure of the model paint sample changes obviously during UV aging. Before aging, the crystal structure of the model paint sample agrees well with the standard crystal structure of minium, but the most noticeable peaks of minium at 26.3{}^{\\circ}, 30.7{}^{\\circ}, and 32.1{}^{\\circ} begin to diminish while the peaks at 24.8{}^{\\circ}, 27.4{}^{\\circ}, and 34.3{}^{\\circ} appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment crystallinity under UV aging. The formation of the basic lead carbonate (lead white) gives a chalky surface.", "score": null, "metadata": {"year": "2019", "chunk_index": 25, "journal": "Color Research & Application", "doi": "10.1002/col.22386", "title": "Degradation of red lead pigment in the oil painting during UV aging", "source": "markdown_output/Degradation of red lead pigment in the oil painting during UV aging.md", "ingest_kind": "existing_chroma", "source_file": "Degradation of red lead pigment in the oil painting during UV aging.md", "authors": [{"family": "Zhao", "given": "Yanrui"}, {"family": "Wang", "given": "Jianli"}, {"family": "Pan", "given": "Aizhao"}, {"family": "He", "given": "Ling"}, {"family": "Simon", "given": "Stefan"}], "volume": "44", "issue": "5", "pages": "790-797", "url": "https://doi.org/10.1002/col.22386"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Therefore, XRD analysis results demonstrate that unstable minium pigment has changed into beta-PbO2 during UV aging. However, for the model paint samples, because the XRD pattern of tung oil is a broad amorphous feature peak with no peak indicative of crystalline phases (Figure 2B), tung oil is proved as a noncrystalline material by aligning with the characteristics of amorphous peaks; therefore, the XRD pattern of model paint sample represents the result of minium pigment. As can been seen in Figure 2B, crystal structure of the model paint sample changes obviously during UV aging. Before aging, the crystal structure of the model paint sample agrees well with the standard crystal structure of minium, but the most noticeable peaks of minium at 26.3{}^{\\circ}, 30.7{}^{\\circ}, and 32.1{}^{\\circ} begin to diminish while the peaks at 24.8{}^{\\circ}, 27.4{}^{\\circ}, and 34.3{}^{\\circ} appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment appear during UV aging, and the final product is identified as 2PbCO3-Pb (OH)2.[30] In addition, the intensity of XRD peak getting weaker suggests the decrease of pigment crystallinity under UV aging. The formation of the basic lead carbonate (lead white) gives a chalky surface.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "beta-PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "In water, the darkening of red lead is induced by light, but when NaHCO3 is added red lead transforms to plattnerite even in darkness.\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "score": null, "snippets": [{"text": "In water, the darkening of red lead is induced by light, but when NaHCO3 is added red lead transforms to plattnerite even in darkness.", "score": null, "metadata": {"ingest_kind": "existing_chroma", "journal": "Journal of Cultural Heritage", "chunk_index": 40, "doi": "10.1016/j.culher.2008.11.001", "source_file": "Degradation of lead-based pigments by salt solutions.md", "year": "2009", "title": "Degradation of lead-based pigments by salt solutions", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "In water, the darkening of red lead is induced by light, but when NaHCO3 is added red lead transforms to plattnerite even in darkness.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "score": null, "metadata": {"title": "Degradation of lead-based pigments by salt solutions", "year": "2009", "doi": "10.1016/j.culher.2008.11.001", "source_file": "Degradation of lead-based pigments by salt solutions.md", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "chunk_index": 42, "journal": "Journal of Cultural Heritage", "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "score": null, "metadata": {"ingest_kind": "existing_chroma", "journal": "Journal of Cultural Heritage", "source_file": "Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "year": "2009", "doi": "10.1016/j.culher.2008.11.001", "chunk_index": 45}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 2, "resolver_scanned": 2314, "resolver_candidates": 64, "resolver_kept": 5, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 2, "lexical_scanned": 2314, "lexical_candidates": 206, "lexical_kept": 6, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/05f12cb7fc2e4449922b32545909a6b0a63c42cb.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv+Oxidant]--> HgSO4 --[Uv+Oxidant]--> Hg2SO4 --[Uv+Oxidant]--> Hg", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2."], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [{"source": "ELERT K, CARDELL C. Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging [J/OL]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019, 216:236-248. DOI: 10.1016/j.saa.2019.03.027.", "snippet": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK\\({}_{\\alpha}\\) radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\(\\times\\) 700 \\(\\upmu\\)m in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg\\({}^{0}\\) and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current). Note that it was not possible to measure the ablation depth achieved during ion-etching using scanning electron microscopy or atomic force microscopy as a result of the sample's high surface roughness (i.e., the relatively small impact of \\(<\\)1 m depth caused by ion-etching could not be distinguished from", "retrieval_origin": "bge_m3", "match": {"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "related", "score": 0.88, "window": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "Hg", "relation_basis": "observed_conversion", "condition_status": "partial", "provenance_level": "unspecified", "reasons": ["condition_partial"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "KEUNE K, BOON JJ. Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings [J/OL]. Analytical Chemistry, 2005. DOI: 10.1021/ac048158f.", "snippet": "The two components in the black product, metallic mercury and residual vermilion, react with chloride supplied by sources external to the vermilion. The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur. Corderoite (HgS\\({}_{2}\\)Cl\\({}_{2}\\)) can easily be formed in a mixture of HgS and NaCl solution kept at room temperature after a long period[3, 9] and will after light exposure degrade into a dark gray product containing (HgCl)\\({}_{2}\\).[9] The formation of corderoite could not have taken place in the first degradation steps, because of the high amount of chloride required that is suggested to accumulate after the blackening. The (HgCl\\({}_{2}\\) formed photodegrades under normal light into HgCl\\({}_{2}\\) and Hg(0).[23] The metallic mercury, derived from the photoreuction in the first step, the corderoite, and the (HgCl)\\({}_{2}\\), react with chloride", "retrieval_origin": "lexical", "match": {"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "related", "score": 0.88, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "partial", "provenance_level": "unspecified", "reasons": ["condition_partial"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "snippet": "the intensity and type of radiation having a rate-determining influence. Besides, schuettetic has been found in cinnabar deposits exposed to natural sunlight in numerous locations, including Almaden (Spain), California and Nevada (USA), Bolivia, Moravia (Czech Republic), and Sonora (Mexico) [48]. According to Bailey et al. [19], this mineral forms through photooxidation of sunlight-exposed cinnabar in the presence of oxygen-bearing surface water. Importantly, the authors acknowledged that HgSO\\({}_{4}\\) might be an intermediate phase during schuettetic formation. In any case, sulfate formation is not limited to cinnabar deposits. Radeport et al. [2, 17] acknowledged the possible oxidation of mercury sulfide to sulfate upon cinnabar degradation in the case of a Gothic wall painting from the monastery of Pedralbes (Barcelona, Spain) and detected mercury sulfate in artificially aged cinnabar pellets.", "retrieval_origin": "crn_provenance", "match": {"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "inferred", "score": 0.87, "window": "According to Bailey et al. [19], this mineral forms through photooxidation of sunlight-exposed cinnabar in the presence of oxygen-bearing surface water. Importantly, the authors acknowledged that HgSO4 might be an intermediate phase during schuettetic formation. In any case, sulfate formation is not limited to cinnabar deposits. Radeport et al. [2, 17] acknowledged the possible oxidation of mercury sulfide to sulfate upon cinnabar degradation in the case of a Gothic wall painting from the monastery of Pedralbes (Barcelona, Spain) and detected mercury sulfate in artificially aged cinnabar pellets.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "mercury sulfide", "product_span": "mercury sulfate", "relation_basis": "author_proposal", "condition_status": "exact", "provenance_level": "unspecified", "reasons": ["relation_author_proposal"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 29, "dense_candidates": 580, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 15, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 218, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/11a1eaafb7fdabf85c8e635c20f2938964555de4.json

@@ -0,0 +1 @@
+{"root_material": "2PbCO3·Pb(OH)2", "path_str": "2PbCO3·Pb(OH)2 --[Fresco]--> β-PbO", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nUpon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.\n\n[1] Evidence classification: edge 1: direct\nUnder a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "ref_list": ["VAGNINI M, VIVANI R, SGAMELLOTTI A, et al. Blackening of lead white: Study of model paintings [J/OL]. Journal of Raman Spectroscopy, 2020. DOI: 10.1002/jrs.5879."], "ref_snippets": [{"text": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.\nUnder a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "score": null, "snippets": [{"text": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.", "score": null, "metadata": {"year": "2020", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "title": "Blackening of lead white: Study of model paintings", "source_file": "Blackening of lead white: Study of model paintings.md", "chunk_index": 21, "ingest_kind": "existing_chroma", "doi": "10.1002/jrs.5879", "journal": "Journal of Raman Spectroscopy", "authors": [{"family": "Vagnini", "given": "Manuela"}, {"family": "Vivani", "given": "Riccardo"}, {"family": "Sgamellotti", "given": "Antonio"}, {"family": "Miliani", "given": "Costanza"}], "volume": "51", "issue": "7", "pages": "1118-1126", "url": "https://doi.org/10.1002/jrs.5879"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "beta-PbO", "condition": "Fresco", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "massicot", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "score": null, "metadata": {"journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.5879", "ingest_kind": "existing_chroma", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "chunk_index": 35, "source_file": "Blackening of lead white: Study of model paintings.md", "year": "2020", "title": "Blackening of lead white: Study of model paintings", "authors": [{"family": "Vagnini", "given": "Manuela"}, {"family": "Vivani", "given": "Riccardo"}, {"family": "Sgamellotti", "given": "Antonio"}, {"family": "Miliani", "given": "Costanza"}], "volume": "51", "issue": "7", "pages": "1118-1126", "url": "https://doi.org/10.1002/jrs.5879"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "resolver"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "beta-PbO", "condition": "Fresco", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "litharge", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 59, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 211, "lexical_kept": 2, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/12e803bb6150e8e5f3b414e296f3989590a54392.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv+Oxidant]--> HgSO4 --[Uv+Moisture]--> Hg", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nAn Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).\n\n[1] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nGenerally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.\n\n[2] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nThe residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.\n\n[3] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nAdditionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].\n\n[4] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nFinally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "ref_list": ["ELERT K, CARDELL C. Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging [J/OL]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019, 216:236-248. DOI: 10.1016/j.saa.2019.03.027.", "KEUNE K, BOON JJ. Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings [J/OL]. Analytical Chemistry, 2005. DOI: 10.1021/ac048158f.", "ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:16. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)"], "ref_snippets": [{"text": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).\nGenerally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.", "score": 0.4447641968727112, "snippets": [{"text": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).", "score": 0.4447641968727112, "metadata": {"doi": "10.1016/j.saa.2019.03.027", "ingest_kind": "existing_chroma", "year": "2019", "journal": "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy", "title": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging", "source": "markdown_output/Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "source_file": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "chunk_index": 24, "authors": [{"family": "Elert", "given": "K."}, {"family": "Cardell", "given": "C."}], "volume": "216", "pages": "236-248", "url": "https://doi.org/10.1016/j.saa.2019.03.027"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "Hg", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Generally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.", "score": null, "metadata": {"year": "2019", "source_file": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "title": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging", "chunk_index": 23, "doi": "10.1016/j.saa.2019.03.027", "ingest_kind": "existing_chroma", "journal": "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy", "source": "markdown_output/Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "authors": [{"family": "Elert", "given": "K."}, {"family": "Cardell", "given": "C."}], "volume": "216", "pages": "236-248", "url": "https://doi.org/10.1016/j.saa.2019.03.027"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Generally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "Hg", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.43365007638931274, "snippets": [{"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.43365007638931274, "metadata": {"doi": "10.1021/ac048158f", "title": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings", "source_file": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "journal": "Analytical Chemistry", "source": "markdown_output/Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "ingest_kind": "existing_chroma", "year": "2005", "chunk_index": 46}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Additionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].", "score": null, "snippets": [{"text": "Additionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].", "score": null, "metadata": {"year": "2021", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "doi": "10.1038/s42004-021-00610-2", "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "journal": "Communications Chemistry", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 3, "ingest_kind": "existing_chroma", "authors": [{"family": "Elert", "given": "Kerstin"}, {"family": "Pérez Mendoza", "given": "Manuel"}, {"family": "Cardell", "given": "Carolina"}], "volume": "4", "issue": "1", "article_number": "174", "url": "https://doi.org/10.1038/s42004-021-00610-2"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Additionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Finally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "score": null, "snippets": [{"text": "Finally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "score": null, "metadata": {"page": "16", "doi": "10.1186/s40494-017-0125-6", "chunk_index": "56", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "year": "2017", "journal": "Heritage Science", "source_file": "On the stability of mediaeval inorganic pigments - a review", "source": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Finally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermillion", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 2, "resolver_scanned": 2314, "resolver_candidates": 16, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 3, "lexical_scanned": 2314, "lexical_candidates": 214, "lexical_kept": 4, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/1527413b7dcf1856afdb156291fe59c3bd7760cf.json

@@ -0,0 +1 @@
+{"root_material": "CuCO3·Cu(OH)2", "path_str": "CuCO3·Cu(OH)2 --[Biogenic+Chloride]--> Cu2Cl(OH)3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nMinerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "ref_list": ["PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1.", "DOMÉNECH‐CARBÓ MT, EDWARDS HGM, DOMÉNECH‐CARBÓ A, et al. An authentication case study: Antonio Palomino versus Vicente Guillo paintings in the vaulted ceiling of the Sant Joan del Mercat church (Valencia, Spain) [J/OL]. Journal of Raman Spectroscopy, 2012. DOI: 10.1002/jrs.3168."], "ref_snippets": [{"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "snippets": [{"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "metadata": {"source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "year": "2024", "doi": "10.1007/s00339-024-07954-1", "journal": "Applied Physics A", "chunk_index": 23, "license": "https://creativecommons.org/licenses/by/4.0", "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "page": 12, "ingest_kind": "pdf_fulltext", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Biogenic+Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 24, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 188, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/15a304fd12f686a1780fa924381f165477a13cbc.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv+Moisture]--> HgSO4 --[Uv+Oxidant]--> Hg2SO4 --[Uv+Oxidant]--> Hg", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nAn Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).\n\n[1] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nGenerally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.\n\n[2] Evidence classification: edge 1: direct\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.\n\n[2] Evidence classification: edge 1: direct\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].\n\n[2] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nAdditionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].\n\n[3] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nThe residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.\n\n[4] Evidence classification: pathway endpoints alpha-HgS -> Hg: direct\nFinally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "ref_list": ["ELERT K, CARDELL C. Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging [J/OL]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019, 216:236-248. DOI: 10.1016/j.saa.2019.03.027.", "ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "KEUNE K, BOON JJ. Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings [J/OL]. Analytical Chemistry, 2005. DOI: 10.1021/ac048158f.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:16. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)"], "ref_snippets": [{"text": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).\nGenerally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.", "score": 0.4930061101913452, "snippets": [{"text": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).", "score": 0.4930061101913452, "metadata": {"source": "markdown_output/Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "year": "2019", "source_file": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "chunk_index": 24, "doi": "10.1016/j.saa.2019.03.027", "journal": "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy", "title": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging", "ingest_kind": "existing_chroma", "authors": [{"family": "Elert", "given": "K."}, {"family": "Cardell", "given": "C."}], "volume": "216", "pages": "236-248", "url": "https://doi.org/10.1016/j.saa.2019.03.027"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s. Ion-etching depth profiles were obtained using Argon for various periods of time (4 keV energy, 10 mA emission current).", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "Hg", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Generally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.", "score": null, "metadata": {"year": "2019", "doi": "10.1016/j.saa.2019.03.027", "ingest_kind": "existing_chroma", "title": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging", "chunk_index": 23, "source_file": "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "journal": "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy", "source": "markdown_output/Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging.md", "authors": [{"family": "Elert", "given": "K."}, {"family": "Cardell", "given": "C."}], "volume": "216", "pages": "236-248", "url": "https://doi.org/10.1016/j.saa.2019.03.027"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Generally, a color differences of DeltaE{}^{\\star}\\simeq3 will be perceptible to the human eye [31]. An Axis Ultra-DLD (Kratos Analytical Ltd., U.K.) was used to determine the quantitative elemental composition and the oxidization state of Hg in cinnabar pigments and in the alteration layer of outdoor (city center of Granada) exposed dosimeters. Analysis was performed using monochromatic AlK{}alpha radiation with a pass energy of 160 (survey scans) and 20 eV (high resolution scans). The analyzed area was -300 \\times 700 \\upmum in size. The C1s transition at 284.6 eV was used as reference to determine binding energies of Hg{}^{0} and Hg5s.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "Hg", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].\nAdditionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].", "score": 0.40642249584198, "snippets": [{"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.", "score": 0.4948519468307495, "metadata": {"ingest_kind": "existing_chroma", "doi": "10.1038/s42004-021-00610-2", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 43, "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "journal": "Communications Chemistry", "year": "2021", "authors": [{"family": "Elert", "given": "Kerstin"}, {"family": "Pérez Mendoza", "given": "Manuel"}, {"family": "Cardell", "given": "Carolina"}], "volume": "4", "issue": "1", "article_number": "174", "url": "https://doi.org/10.1038/s42004-021-00610-2"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "mercury sulfate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": 0.40642249584198, "metadata": {"source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "doi": "10.1038/s42004-021-00610-2", "year": "2021", "ingest_kind": "existing_chroma", "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 42, "journal": "Communications Chemistry", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "authors": [{"family": "Elert", "given": "Kerstin"}, {"family": "Pérez Mendoza", "given": "Manuel"}, {"family": "Cardell", "given": "Carolina"}], "volume": "4", "issue": "1", "article_number": "174", "url": "https://doi.org/10.1038/s42004-021-00610-2"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "mercury sulfate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Additionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].", "score": null, "metadata": {"doi": "10.1038/s42004-021-00610-2", "journal": "Communications Chemistry", "chunk_index": 3, "year": "2021", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "ingest_kind": "existing_chroma", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "authors": [{"family": "Elert", "given": "Kerstin"}, {"family": "Pérez Mendoza", "given": "Manuel"}, {"family": "Cardell", "given": "Carolina"}], "volume": "4", "issue": "1", "article_number": "174", "url": "https://doi.org/10.1038/s42004-021-00610-2"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Additionally, the imperative role played by chlorides has been recognized, either as a catalyst in the redox reaction of cinnabar or as intermediate reaction products that are subsequently photochemically reduced to metallic mercury[6, 10].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.45197176933288574, "snippets": [{"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.45197176933288574, "metadata": {"ingest_kind": "existing_chroma", "chunk_index": 46, "doi": "10.1021/ac048158f", "journal": "Analytical Chemistry", "source": "markdown_output/Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "source_file": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "year": "2005", "title": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Finally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "score": null, "snippets": [{"text": "Finally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "score": null, "metadata": {"page": "16", "doi": "10.1186/s40494-017-0125-6", "chunk_index": "56", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "year": "2017", "journal": "Heritage Science", "source_file": "On the stability of mediaeval inorganic pigments - a review", "source": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Finally, the photodegradation of vermillion was explained in terms of formation of metallic mercury and HgCl 2, due to the halogen impurities present in the pigment, identi - fied thanks to secondary ion mass spectrometry (SIMS) analysis [207], and to X-ray spectroscopic analysis [208].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermillion", "product_span": "metallic mercury", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 29, "dense_candidates": 580, "dense_kept": 4, "resolver_scanned": 2314, "resolver_candidates": 15, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 4, "lexical_scanned": 2314, "lexical_candidates": 218, "lexical_kept": 6, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/161e820820e5196de774b76b895ea9dcc24b9541.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Uv]--> CuO", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nThe effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124].", "ref_list": ["On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845."], "ref_snippets": [{"text": "The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124].", "score": 0.4847486615180969, "snippets": [{"text": "The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124].", "score": 0.4847486615180969, "metadata": {"ingest_kind": "pdf_fulltext", "journal": "Heritage Science", "year": "2017", "source_file": "On the stability of mediaeval inorganic pigments - a review", "doi": "10.1186/s40494-017-0125-6", "page": "13", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "source": "On the stability of mediaeval inorganic pigments - a review", "chunk_index": "40"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "azurite", "product_span": "CuO", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 39, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 237, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/162ec05c8d8d624f9c30f8fc40c1fc205cd2d287.json

@@ -0,0 +1 @@
+{"root_material": "CuCO3·Cu(OH)2", "path_str": "CuCO3·Cu(OH)2 --[12000lux+1.5W/m2+60℃+90%RH]--> CuO", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["CRN source: In-house aging experiment"], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": null}], "related_context": [{"source": "Blackening of copper pigments in wall paintings: impact of the fresco technique and the chemical composition of the pigments [J/OL]. Heritage Science, 2026:2. DOI: 10.1038/s40494-026-02461-3. (bibliographic metadata partially available)", "snippet": "ondary carbonates (malachite) 8,17–20.T h em o s tc o m m o n l y reported alteration, however, is blackening, generally attributed to the for- mation of tenorite (CuO) under conditions of high humidity and alkalinity in lime-based substrates2,21–27. Tenorite formation may also result from thermal damage28 or laser irradiation 29,30.I na d d i t i o n ,i n t e r a c t i o n sw i t h pollutant gases and acids can produce dark copper compounds such as copper sulphides (covellite) 31,32. Despite this extensive research, the mechanisms driving CuO formation under alkaline fresco conditions remain largely unclear. Importantly, most studies have focused on natural azurite and malachite powders, while other copper pigments—particularly silicates and acetates—have received far less attention. Furthermore, factors such as pigment origin, impurities, a nd the formation of copper species other than tenorite have rarely been explored in lime-based mural systems. Consequently, the causes and variability of blackening in fresco paintings are still not fully explained. The present study addresses this gap by examining a representative set of copper pigments applied directly onto lime-based substrates in order to clarify the mechanisms responsible for blackening.", "retrieval_origin": "resolver", "match": {"edge_index": 1, "reactant": "CuCO3·Cu(OH)2", "product": "CuO", "condition": "12000lux+1.5W/m2+60℃+90%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.8, "window": "ondary carbonates (malachite) 8,17–20.T h em o s tc o m m o n l y reported alteration, however, is blackening, generally attributed to the for- mation of tenorite (CuO) under conditions of high humidity and alkalinity in lime-based substrates2,21–27.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "tenorite", "relation_basis": "observed_conversion", "condition_status": "unstated", "provenance_level": "unspecified", "reasons": ["condition_unstated"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "Blackening of copper pigments in wall paintings: impact of the fresco technique and the chemical composition of the pigments [J/OL]. Heritage Science, 2026:6. DOI: 10.1038/s40494-026-02461-3. (bibliographic metadata partially available)", "snippet": "bserved. Egyptian blue (EGB-F) remained chromatically stable, retaining its bluish hue and showing no reaction halos under SEM, confirming the high stability of cuprorivaite particles. Sporadic dark Cu- rich particles were occasionally detected (Fig. 6a, b), likely related to the raw materials used during pigment synthesis 8. EDS line-scan analysis of this particle (Fig. 6b) showed a similar spectrum to that observed in basic Cu-carbonates. However, these blackish particles did not affect the overall appearance of the paint layer. In contrast, chrysocolla (CHR-F) Table 2 | Mineralogical characterization by μXRD of the fresco paint mock-ups Fresco samples Assigned to the fresco technique Present in the raw pigment Alteration products Basic Cu-carbonates AZN-F Calcite, CaCO3 Azurite, Cu3(CO3)2(OH)2 Tenorite, CuO Portlandite, Ca(OH)2 Kaolinite, Al2Si2O5(OH)4 Quartz, SiO2 Phlogopite, KMg3AlSi3O10(F,OH)2 AZS-F Calcite, CaCO3 - Portlandite, Ca(OH)2 Azurite, Cu3(CO3)2(OH)2 AZP-F Calcite, CaCO3 Azurite, Cu3(CO3)2(OH)2 Tenorite, CuO Quartz, SiO2 - MAN-F Calcite, CaCO3 Malachite, CuCO3Cu(OH)2 Portlandite, Ca(OH)2 Cuprite, Cu2O Quartz, SiO2 Haematite, Fe2O3 - MAS-F Calcite, CaCO3 Malachite, CuCO3Cu(OH)2 - Portlandite, Ca(OH)2 Quartz, SiO2 Cu-silicates EGB-F Calcite, CaCO3 Cuprorivaite, CaCuSi4O10 - Portlandite, Ca(OH)2 CHR-F Calcite, CaCO3 Chrysocolla, CuSiO3 - Portlandite, Ca(OH)2 Cu-acetate VER-F Calcite, CaCO3 - Cuprite, Cu 2O Portlandite, Ca(OH)2 Quartz, SiO2 Vaterite, CaCO3 Samples were taken after 1 year left under laboratory conditions (20 ± 2 °C and 60 ± 10% RH).", "retrieval_origin": "resolver", "match": {"edge_index": 1, "reactant": "CuCO3·Cu(OH)2", "product": "CuO", "condition": "12000lux+1.5W/m2+60℃+90%RH", "evidence_scope": "edge", "verdict": "qualified", "score": 0.75, "window": "In contrast, chrysocolla (CHR-F) Table 2 | Mineralogical characterization by μXRD of the fresco paint mock-ups Fresco samples Assigned to the fresco technique Present in the raw pigment Alteration products Basic Cu-carbonates AZN-F Calcite, CaCO3 Azurite, Cu3(CO3)2(OH)2 Tenorite, CuO Portlandite, Ca(OH)2 Kaolinite, Al2Si2O5(OH)4 Quartz, SiO2 Phlogopite, KMg3AlSi3O10(F,OH)2 AZS-F Calcite, CaCO3 - Portlandite, Ca(OH)2 Azurite, Cu3(CO3)2(OH)2 AZP-F Calcite, CaCO3 Azurite, Cu3(CO3)2(OH)2 Tenorite, CuO Quartz, SiO2 - MAN-F Calcite, CaCO3 Malachite, CuCO3Cu(OH)2 Portlandite, Ca(OH)2 Cuprite, Cu2O Quartz, SiO2 Haematite, Fe2O3 - MAS-F Calcite, CaCO3 Malachite, CuCO3Cu(OH)2 - Portlandite, Ca(OH)2 Quartz, SiO2 Cu-silicates EGB-F Calcite, CaCO3 Cuprorivaite, CaCuSi4O10 - Portlandite, Ca(OH)2 CHR-F Calcite, CaCO3 Chrysocolla, CuSiO3 - Portlandite, Ca(OH)2 Cu-acetate VER-F Calcite, CaCO3 - Cuprite, Cu2O Portlandite, Ca(OH)2 Quartz, SiO2 Vaterite, CaCO3 Samples were taken after 1 year left under laboratory conditions (20 ± 2 °C and 60 ± 10% RH).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "tenorite", "relation_basis": "product_identification", "condition_status": "partial", "provenance_level": "unspecified", "reasons": ["relation_product_identification", "condition_partial"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "snippet": "is formed. The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124]. Malachite (CuCO3·Cu(OH)2, green) Malachite (CuCO 3·Cu(OH)2) is more stable than azurite (2CuCO 3·Cu(OH)2) and verdigris (xCu(CH3COO2)·yCu(OH)2·zH2O), therefore showing less or slower reactivity towards many factors [119, 123]. It is known to be permanent in all binding media, light - fast and alkali proof. Its deeper colour is obtained by coarse grinding, and as a consequence of having relatively low refractive index, it shows better performances in tempera than in oil [50, 126]. Due to its chemical com - position, malachite is subject to interactions with acids, bases, humidity, temperature and circulating ions. In presence of humidity, malachite stains can be observed, which are actually caused by proteinaceous binders deg - radation [64]. Moreover, ions such as Cl − present in the mortar, sand or in the bricks, can react with the basic car- bonate to form copper hydroxychlorides ((Cu 2Cl(OH)3) atacamite, clinoatacamite, paratacamite botallackite) [119, 121, 123, 126–128] and the copper chloride nan - tokite [103]. Sulphate ions are also likely to be present in wall paintings, especially from the degradation of calcite to gypsum, from gypsum preparation layers [53], or from SO 2/SO3 pollution.", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "CuCO3·Cu(OH)2", "product": "CuO", "condition": "12000lux+1.5W/m2+60℃+90%RH", "evidence_scope": "edge", "verdict": "qualified", "score": 0.67, "window": "The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124]. Malachite (CuCO3·Cu(OH)2, green) Malachite (CuCO 3·Cu(OH)2) is more stable than azurite (2CuCO 3·Cu(OH)2) and verdigris (xCu(CH3COO2)·yCu(OH)2·zH2O), therefore showing less or slower reactivity towards many factors [119, 123].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "malachite", "product_span": "CuO", "relation_basis": "product_identification", "condition_status": "unstated", "provenance_level": "unspecified", "reasons": ["relation_product_identification", "condition_unstated"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 28, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 163, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/1eab3d122a45a246efcacb8e92b21aa09ea0b37c.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Moisture]--> CuCO3·Cu(OH)2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nBlack colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "ref_list": ["POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "CARDELL C, HERRERA A, GUERRA I, et al. Pigment-size effect on the physico-chemical behavior of azurite-tempera dosimeters upon natural and accelerated photo aging [J/OL]. Dyes and Pigments, 2017. DOI: 10.1016/j.dyepig.2017.02.001."], "ref_snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "metadata": {"year": "2020", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "chunk_index": 7, "journal": "Minerals", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "ingest_kind": "pdf_direct", "doi": "10.3390/min10050424", "source": "pdf_direct/min10050424_part2.pdf"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 148, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 252, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/1fae62eed06440517bbd2f745709a92801b69c3d.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Moisture]--> CuCO3·Cu(OH)2 --[Biogenic+Sulfate]--> Cu4SO4(OH)6", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nBlack colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "ref_list": ["POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "CARDELL C, HERRERA A, GUERRA I, et al. Pigment-size effect on the physico-chemical behavior of azurite-tempera dosimeters upon natural and accelerated photo aging [J/OL]. Dyes and Pigments, 2017. DOI: 10.1016/j.dyepig.2017.02.001."], "ref_snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "metadata": {"title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "journal": "Minerals", "year": "2020", "ingest_kind": "pdf_direct", "chunk_index": 7, "source": "pdf_direct/min10050424_part2.pdf", "doi": "10.3390/min10050424"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 159, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 297, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/20e24f7154446e9fe75db49f51d62a3f5ae93bd3.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[Acid]--> β-PbO2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nIn acidic solution, red lead undergoes a disproportionation reaction, resulting in the formation of plattnerite - PbO2 (reaction 1) [17]: Pb3O4+4H^{+}\\rightarrowPbO2+2 Pb^{2+}+2H2O\n\n[1] Evidence classification: edge 1: direct\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\n\n[1] Evidence classification: edge 1: direct\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite\n\n[1] Evidence classification: edge 1: direct\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite \\begin{table} \\begin{tabular}{l l l l l l} No. & Type & Area of wall painting & Sample colour & Major components & Minor components \\\\ \\hline 1 & Fragment & Southern wall, dark line between & Black and grey & Plattnerite, PbMg(CO3)2, calcite & Hydrocerussite, scrutinyite \\\\ 2 & Fragment & Southern wall, right part of & White, ochre, black & Plattnerite, cervusite, & Calcite, scrutinyite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 3 & Fragment & Southern wall, right part of & Black, white, ochre & Plattnerite, cervusite, & Calcite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 5 & Fragment & Southern wall, halo of prophet in & Black, white & Calcite, plattnerite, cervusite & Gypsum, massicot, scrutinyite \\\\ & & the Nativity scene & & & \\\\ 6 & Fragment & Southern wall, dark line between & Black, white, red & Plattnerite & Calcite, gypsum, scrutinyite \\\\ & & Measurement 1", "ref_list": ["KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001."], "ref_snippets": [{"text": "In acidic solution, red lead undergoes a disproportionation reaction, resulting in the formation of plattnerite - PbO2 (reaction 1) [17]: Pb3O4+4H^{+}\\rightarrowPbO2+2 Pb^{2+}+2H2O\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite \\begin{table} \\begin{tabular}{l l l l l l} No. & Type & Area of wall painting & Sample colour & Major components & Minor components \\\\ \\hline 1 & Fragment & Southern wall, dark line between & Black and grey & Plattnerite, PbMg(CO3)2, calcite & Hydrocerussite, scrutinyite \\\\ 2 & Fragment & Southern wall, right part of & White, ochre, black & Plattnerite, cervusite, & Calcite, scrutinyite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 3 & Fragment & Southern wall, right part of & Black, white, ochre & Plattnerite, cervusite, & Calcite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 5 & Fragment & Southern wall, halo of prophet in & Black, white & Calcite, plattnerite, cervusite & Gypsum, massicot, scrutinyite \\\\ & & the Nativity scene & & & \\\\ 6 & Fragment & Southern wall, dark line between & Black, white, red & Plattnerite & Calcite, gypsum, scrutinyite \\\\ & & Measurement 1", "score": null, "snippets": [{"text": "In acidic solution, red lead undergoes a disproportionation reaction, resulting in the formation of plattnerite - PbO2 (reaction 1) [17]: Pb3O4+4H^{+}\\rightarrowPbO2+2 Pb^{2+}+2H2O", "score": null, "metadata": {"doi": "10.1016/j.culher.2008.11.001", "title": "Degradation of lead-based pigments by salt solutions", "journal": "Journal of Cultural Heritage", "source_file": "Degradation of lead-based pigments by salt solutions.md", "year": "2009", "chunk_index": 4, "ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "authors": [{"family": "Kotulanová", "given": "Eva"}, {"family": "Bezdička", "given": "Petr"}, {"family": "Hradil", "given": "David"}, {"family": "Hradilová", "given": "Janka"}, {"family": "Švarcová", "given": "Silvie"}, {"family": "Grygar", "given": "Tomáš"}], "volume": "10", "issue": "3", "pages": "367-378", "url": "https://doi.org/10.1016/j.culher.2008.11.001"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Acid", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "In acidic solution, red lead undergoes a disproportionation reaction, resulting in the formation of plattnerite - PbO2 (reaction 1) [17]: Pb3O4+4H^{+}\\rightarrowPbO2+2 Pb^{2+}+2H2O", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "score": null, "metadata": {"year": "2009", "chunk_index": 42, "doi": "10.1016/j.culher.2008.11.001", "journal": "Journal of Cultural Heritage", "ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "source_file": "Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "authors": [{"family": "Kotulanová", "given": "Eva"}, {"family": "Bezdička", "given": "Petr"}, {"family": "Hradil", "given": "David"}, {"family": "Hradilová", "given": "Janka"}, {"family": "Švarcová", "given": "Silvie"}, {"family": "Grygar", "given": "Tomáš"}], "volume": "10", "issue": "3", "pages": "367-378", "url": "https://doi.org/10.1016/j.culher.2008.11.001"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Acid", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "score": null, "metadata": {"year": "2009", "journal": "Journal of Cultural Heritage", "source_file": "Degradation of lead-based pigments by salt solutions.md", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "ingest_kind": "existing_chroma", "chunk_index": 45, "doi": "10.1016/j.culher.2008.11.001", "authors": [{"family": "Kotulanová", "given": "Eva"}, {"family": "Bezdička", "given": "Petr"}, {"family": "Hradil", "given": "David"}, {"family": "Hradilová", "given": "Janka"}, {"family": "Švarcová", "given": "Silvie"}, {"family": "Grygar", "given": "Tomáš"}], "volume": "10", "issue": "3", "pages": "367-378", "url": "https://doi.org/10.1016/j.culher.2008.11.001"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Acid", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite \\begin{table} \\begin{tabular}{l l l l l l} No. & Type & Area of wall painting & Sample colour & Major components & Minor components \\\\ \\hline 1 & Fragment & Southern wall, dark line between & Black and grey & Plattnerite, PbMg(CO3)2, calcite & Hydrocerussite, scrutinyite \\\\ 2 & Fragment & Southern wall, right part of & White, ochre, black & Plattnerite, cervusite, & Calcite, scrutinyite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 3 & Fragment & Southern wall, right part of & Black, white, ochre & Plattnerite, cervusite, & Calcite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 5 & Fragment & Southern wall, halo of prophet in & Black, white & Calcite, plattnerite, cervusite & Gypsum, massicot, scrutinyite \\\\ & & the Nativity scene & & & \\\\ 6 & Fragment & Southern wall, dark line between & Black, white, red & Plattnerite & Calcite, gypsum, scrutinyite \\\\ & & Measurement 1", "score": null, "metadata": {"ingest_kind": "existing_chroma", "source_file": "Degradation of lead-based pigments by salt solutions.md", "chunk_index": 46, "doi": "10.1016/j.culher.2008.11.001", "title": "Degradation of lead-based pigments by salt solutions", "journal": "Journal of Cultural Heritage", "year": "2009", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "authors": [{"family": "Kotulanová", "given": "Eva"}, {"family": "Bezdička", "given": "Petr"}, {"family": "Hradil", "given": "David"}, {"family": "Hradilová", "given": "Janka"}, {"family": "Švarcová", "given": "Silvie"}, {"family": "Grygar", "given": "Tomáš"}], "volume": "10", "issue": "3", "pages": "367-378", "url": "https://doi.org/10.1016/j.culher.2008.11.001"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Acid", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite \\begin{table} \\begin{tabular}{l l l l l l} No. & Type & Area of wall painting & Sample colour & Major components & Minor components \\\\ \\hline 1 & Fragment & Southern wall, dark line between & Black and grey & Plattnerite, PbMg(CO3)2, calcite & Hydrocerussite, scrutinyite \\\\ 2 & Fragment & Southern wall, right part of & White, ochre, black & Plattnerite, cervusite, & Calcite, scrutinyite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 3 & Fragment & Southern wall, right part of & Black, white, ochre & Plattnerite, cervusite, & Calcite \\\\ & & Massacre of the Innocent scene & PbMg(CO3)2, hydrocerussite & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 4 & Fragment & Southern wall, outline of the & Black, white & Plattnerite & Calcite, cervusite, scrutinyite \\\\ & & finger of Isaiah & & & \\\\ 5 & Fragment & Southern wall, halo of prophet in & Black, white & Calcite, plattnerite, cervusite & Gypsum, massicot, scrutinyite \\\\ & & the Nativity scene & & & \\\\ 6 & Fragment & Southern wall, dark line between & Black, white, red & Plattnerite & Calcite, gypsum, scrutinyite \\\\ & & Measurement 1", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 64, "resolver_kept": 3, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 201, "lexical_kept": 3, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/26e7deb714459d7fb1fafc366bc5bcdb3c847c2b.json

@@ -0,0 +1 @@
+{"root_material": "CuCO3·Cu(OH)2", "path_str": "CuCO3·Cu(OH)2 --[Biogenic+Sulfate]--> Cu4SO4(OH)6", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["CASTRO K, SARMIENTO A, MARTÍNEZ-ARKARAZO I, et al. Green Copper Pigments Biodegradation in Cultural Heritage: From Malachite to Moolooite, Thermodynamic Modeling, X-ray Fluorescence, and Raman Evidence [J/OL]. Analytical Chemistry, 2008. DOI: 10.1021/ac800255w."], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [{"source": "CASTRO K, SARMIENTO A, MARTÍNEZ-ARKARAZO I, et al. Green Copper Pigments Biodegradation in Cultural Heritage: From Malachite to Moolooite, Thermodynamic Modeling, X-ray Fluorescence, and Raman Evidence [J/OL]. Analytical Chemistry, 2008. DOI: 10.1021/ac800255w.", "snippet": "Unfortunately no other bands could be obtained from the green area. As in the previous cases, these sculptures seem to have suffered a biological attack, as the presence of calcium oxalate suggests. Unfortunately, the raw green pigment was completely decayed (it was quantitatively transformed into moolooite) and it was not possible to identify it. Thermodynamic Modeling, Degradation Mechanisms, and Reactions. According to the experimental data obtained, it is possible to propose several degradation routes (mecha- nisms) for copper green pigments, such as malachite (Cu 2- CO3(OH)2) to moolooite (CuC 2O4·nH2O), passing through copper hydroxysulphates posnjakite (Cu 4SO4(OH)6·H2O), bro - chantite (Cu 4SO4(OH)6), antlerite (Cu 3SO4(OH)4), etc., and/ or copper hydroxychlorides atacamite (Cu 2Cl(OH) 3), parata - camite (Cu 2Cl(OH) 3), etc., depending on the chemical condi- tions. In order to assess the degradation pathways and confirm the thermodynamic stability of all the solid phases identified from the experimental data obtained, we have performed a chemical reaction simulation using the MEDUSA software. This modeling Figure 3. Chemical simulation by MEDUSA software of a micro- biological attack (continuous increasing of oxalic acid concentration) over malachite in the presence of high levels of sulfate. Malachite (Cu 2CO3(OH)2), atacamite (CuCl 2·3Cu(OH)2), brochantite (Cu 4SO4- (OH)6), and antlerite (Cu 3SO4(OH)4) are the solids appearing as predominant species. Figure 4.", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "CuCO3·Cu(OH)2", "product": "Cu4SO4(OH)6", "condition": "Biogenic+Sulfate", "evidence_scope": "edge", "verdict": "qualified", "score": 0.87, "window": "According to the experimental data obtained, it is possible to propose several degradation routes (mecha- nisms) for copper green pigments, such as malachite (Cu 2- CO3(OH)2) to moolooite (CuC 2O4·nH2O), passing through copper hydroxysulphates posnjakite (Cu4SO4(OH)6·H2O), bro - chantite (Cu4SO4(OH)6), antlerite (Cu3SO4(OH)4), etc., and/ or copper hydroxychlorides atacamite (Cu2Cl(OH)3), parata - camite (Cu2Cl(OH)3), etc., depending on the chemical condi- tions. In order to assess the degradation pathways and confirm the thermodynamic stability of all the solid phases identified from the experimental data obtained, we have performed a chemical reaction simulation using the MEDUSA software. This modeling Figure 3. Chemical simulation by MEDUSA software of a micro- biological attack (continuous increasing of oxalic acid concentration) over malachite in the presence of high levels of sulfate. Malachite (Cu2CO3(OH)2), atacamite (CuCl 2·3Cu(OH)2), brochantite (Cu4SO4- (OH)6), and antlerite (Cu3SO4(OH)4) are the solids appearing as predominant species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "copper green", "product_span": "brochantite", "relation_basis": "product_identification", "condition_status": "exact", "provenance_level": "unspecified", "reasons": ["relation_product_identification"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "The Use of X-Ray Photoelectron Spectroscopy in Studying Azurite and Malachite as Minerals, Pigments and in Secondary Products on Copper Objects [J/OL]. JOJ Material Science, 2026:9. DOI: 10.19080/jojms.2026.10.555788. (bibliographic metadata partially available)", "snippet": "e changes in binding energies during the degradation process Figure 3. During the initial corrosion process, metallic copper (Cu0) is converted to Cu2O (cuprite). The Cu 2p core level spectrum is characterized by binding energies around 932.5eV [45]. The XPS analysis on copper surfaces exposed for long durations in different atmospheric conditions showed that during the initial stages, cuprite is the dominant corrosion product, where copper in Cu2O has a lower binding energy compared to Cu (II). When copper is exposed to the atmosphere for long durations, the corrosion products gradually change due to the presence of sulfur dioxide in the atmosphere. During this period, copper is converted from Cu2O to brochantite (Cu4SO4(OH)6·2H2O). The Cu (II) in brochantite is characterized by binding energies ranging from 934-935eV, showing an increase in the copper oxidation state, similar to the binding energies in the azurite and malachite minerals, as discussed in the literature by Kloprogge & Wood [40]. A particularly illustrative case of the evolution of binding energies during the process of corrosion can be exemplified by the depth profiling of multi-layered systems of patina. In the urban atmospheric environment with mixed acid rain-induced acceleration of the corrosion process, the top layer of the patina contains Cu (II)-based compounds such as sulfates, oxides, and hydroxy oxides. In the interfacial region of the corrosion product layer and the underlying Cu metal, Cu 2O is found to be favored.", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "CuCO3·Cu(OH)2", "product": "Cu4SO4(OH)6", "condition": "Biogenic+Sulfate", "evidence_scope": "edge", "verdict": "qualified", "score": 0.75, "window": "When copper is exposed to the atmosphere for long durations, the corrosion products gradually change due to the presence of sulfur dioxide in the atmosphere. During this period, copper is converted from Cu2O to brochantite (Cu4SO4(OH)6·2H2O). The Cu (II) in brochantite is characterized by binding energies ranging from 934-935eV, showing an increase in the copper oxidation state, similar to the binding energies in the azurite and malachite minerals, as discussed in the literature by Kloprogge & Wood [40].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "brochantite", "relation_basis": "product_identification", "condition_status": "partial", "provenance_level": "unspecified", "reasons": ["relation_product_identification", "condition_partial"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 18, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 181, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/2ae7d0ca8e7289a53e8dedc08130d5ab913b04e5.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Chloride]--> α-Hg3S2Cl2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nThe residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "ref_list": ["KEUNE K, BOON JJ. Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings [J/OL]. Analytical Chemistry, 2005. DOI: 10.1021/ac048158f.", "CHAPPÉ M, HILDENHAGEN J, DICKMANN K, et al. Laser irradiation of medieval pigments at IR, VIS and UV wavelengths [J/OL]. Journal of Cultural Heritage, 2003. DOI: 10.1016/s1296-2074(02)01206-2.", "COTTE M, SUSINI J, METRICH N, et al. Blackening of Pompeian Cinnabar Paintings: X-ray Microspectroscopy Analysis [J/OL]. Analytical Chemistry, 2006. DOI: 10.1021/ac0612224."], "ref_snippets": [{"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.42070335149765015, "snippets": [{"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.42070335149765015, "metadata": {"doi": "10.1021/ac048158f", "year": "2005", "journal": "Analytical Chemistry", "title": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings", "source_file": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "source": "markdown_output/Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "ingest_kind": "existing_chroma", "chunk_index": 46, "authors": [{"family": "Keune", "given": "Katrien"}, {"family": "Boon", "given": "Jaap J."}], "volume": "77", "issue": "15", "pages": "4742-4750", "url": "https://doi.org/10.1021/ac048158f"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "alpha-Hg3S2Cl2", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "corderoite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 11, "dense_candidates": 220, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 14, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 200, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/2bdf1cf189143389be2f028648909a518a6a36f5.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Moisture]--> CuCO3·Cu(OH)2 --[Biogenic+Sulfate]--> Cu4SO4(OH)6 --[Biogenic+Sulfate]--> Cu3SO4(OH)4", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nBlack colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "ref_list": ["POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "CARDELL C, HERRERA A, GUERRA I, et al. Pigment-size effect on the physico-chemical behavior of azurite-tempera dosimeters upon natural and accelerated photo aging [J/OL]. Dyes and Pigments, 2017. DOI: 10.1016/j.dyepig.2017.02.001."], "ref_snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "metadata": {"year": "2020", "ingest_kind": "pdf_direct", "doi": "10.3390/min10050424", "journal": "Minerals", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "source": "pdf_direct/min10050424_part2.pdf", "chunk_index": 7, "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 29, "dense_candidates": 580, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 163, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 299, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/2cbc69581f8f87272a59c929bd4f3e937839b63c.json

@@ -0,0 +1 @@
+{"root_material": "2PbCO3·Pb(OH)2", "path_str": "2PbCO3·Pb(OH)2 --[CO2]--> PbCO3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nPhase abbreviations: Ce: cerussite (PbCO3); H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO). Figure 3: X-ray pattern of reaction product of lead white pigment with solution of Na2SO4. Phase abbreviations: Ce: cerussite (PbCO3); S: Pb4(CO3)2(SO4)(OH)2; H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO).\n\n[2] Evidence classification: edge 1: direct\nblack compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2}\n\n[2] Evidence classification: edge 1: direct\nblack compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2} Hydrogen sulfide concentrations were measured where the drawings were stored in 2018.\n\n[3] Evidence classification: edge 1: direct\nFigure 5: Diffractograms of corussite (I, black) and hydrocerussite (II, grey) after reaction with NaClO (H = halite, P=plattnerite, C=cerussite, S= scrutinyite).\n\n[3] Evidence classification: edge 1: direct\nHydrocerussite forms scrutinyite to a larger extent than plattenrite, whereas cerussite turns mainly into plattenrite with small contents of scrutinyite.", "ref_list": ["KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001.", "PASTORELLI G, MIRANDA ASO, CLERICI EA, et al. Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation [J/OL]. Microchemical Journal, 2024. DOI: 10.1016/j.microc.2024.109912.", "VAGNINI M, VIVANI R, SGAMELLOTTI A, et al. Blackening of lead white: Study of model paintings [J/OL]. Journal of Raman Spectroscopy, 2020. DOI: 10.1002/jrs.5879."], "ref_snippets": [{"text": "Phase abbreviations: Ce: cerussite (PbCO3); H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO). Figure 3: X-ray pattern of reaction product of lead white pigment with solution of Na2SO4. Phase abbreviations: Ce: cerussite (PbCO3); S: Pb4(CO3)2(SO4)(OH)2; H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO).", "score": 0.45802968740463257, "snippets": [{"text": "Phase abbreviations: Ce: cerussite (PbCO3); H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO). Figure 3: X-ray pattern of reaction product of lead white pigment with solution of Na2SO4. Phase abbreviations: Ce: cerussite (PbCO3); S: Pb4(CO3)2(SO4)(OH)2; H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO).", "score": 0.45802968740463257, "metadata": {"journal": "Journal of Cultural Heritage", "chunk_index": 31, "doi": "10.1016/j.culher.2008.11.001", "year": "2009", "title": "Degradation of lead-based pigments by salt solutions", "source_file": "Degradation of lead-based pigments by salt solutions.md", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "ingest_kind": "existing_chroma", "authors": [{"family": "Kotulanová", "given": "Eva"}, {"family": "Bezdička", "given": "Petr"}, {"family": "Hradil", "given": "David"}, {"family": "Hradilová", "given": "Janka"}, {"family": "Švarcová", "given": "Silvie"}, {"family": "Grygar", "given": "Tomáš"}], "volume": "10", "issue": "3", "pages": "367-378", "url": "https://doi.org/10.1016/j.culher.2008.11.001"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Phase abbreviations: Ce: cerussite (PbCO3); H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO). Figure 3: X-ray pattern of reaction product of lead white pigment with solution of Na2SO4. Phase abbreviations: Ce: cerussite (PbCO3); S: Pb4(CO3)2(SO4)(OH)2; H: hydrocerussite (Pb3(CO3)2(OH)2); Ma: massicot (PbO).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "cerussite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "black compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2}\nblack compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2} Hydrogen sulfide concentrations were measured where the drawings were stored in 2018.", "score": null, "snippets": [{"text": "black compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2}", "score": null, "metadata": {"doi": "10.1016/j.microc.2024.109912", "ingest_kind": "existing_chroma", "source_file": "Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation.md", "title": "Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation", "year": "2024", "journal": "Microchemical Journal", "chunk_index": 39, "source": "markdown_output/Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation.md"}, "evidence_level": "edge_direct", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "black compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2}", "reactant_match": "exact", "product_match": "exact", "reactant_span": "2PbCO3Pb(OH)2", "product_span": "PbCO3", "relation_basis": "explicit_equation", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "black compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2} Hydrogen sulfide concentrations were measured where the drawings were stored in 2018.", "score": null, "metadata": {"year": "2024", "doi": "10.1016/j.microc.2024.109912", "title": "Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation", "source": "markdown_output/Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation.md", "journal": "Microchemical Journal", "ingest_kind": "existing_chroma", "source_file": "Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation.md", "chunk_index": 40}, "evidence_level": "edge_direct", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "black compound, was identified near the surface, leading to unsightly blackening of the highlights. The formation of this black phase was attributed to improper conservation conditions that exposed the artwork to elevated levels of H2S. The reaction between lead carbonates and H2S was discussed by Smith et al. [36] and is described by the following chemical equations: 2PbCO3Pb(OH)2\\text{ (s) + 3H2S (g) \\rightarrow 3PBS (s) + 2CO2 (g) + 4H2O (l)} \\tag{1} PbCO3\\text{ (s) + H2S (g) \\rightarrow PbS (s) + CO2 (g) + H2O (l)} \\tag{2} Hydrogen sulfide concentrations were measured where the drawings were stored in 2018.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "2PbCO3Pb(OH)2", "product_span": "PbCO3", "relation_basis": "explicit_equation", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Figure 5: Diffractograms of corussite (I, black) and hydrocerussite (II, grey) after reaction with NaClO (H = halite, P=plattnerite, C=cerussite, S= scrutinyite).\nHydrocerussite forms scrutinyite to a larger extent than plattenrite, whereas cerussite turns mainly into plattenrite with small contents of scrutinyite.", "score": null, "snippets": [{"text": "Figure 5: Diffractograms of corussite (I, black) and hydrocerussite (II, grey) after reaction with NaClO (H = halite, P=plattnerite, C=cerussite, S= scrutinyite).", "score": null, "metadata": {"doi": "10.1002/jrs.5879", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "source_file": "Blackening of lead white: Study of model paintings.md", "title": "Blackening of lead white: Study of model paintings", "chunk_index": 31, "year": "2020", "ingest_kind": "existing_chroma", "journal": "Journal of Raman Spectroscopy"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Figure 5: Diffractograms of corussite (I, black) and hydrocerussite (II, grey) after reaction with NaClO (H = halite, P=plattnerite, C=cerussite, S= scrutinyite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "cerussite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Hydrocerussite forms scrutinyite to a larger extent than plattenrite, whereas cerussite turns mainly into plattenrite with small contents of scrutinyite.", "score": null, "metadata": {"source": "markdown_output/Blackening of lead white: Study of model paintings.md", "ingest_kind": "existing_chroma", "journal": "Journal of Raman Spectroscopy", "source_file": "Blackening of lead white: Study of model paintings.md", "doi": "10.1002/jrs.5879", "title": "Blackening of lead white: Study of model paintings", "year": "2020", "chunk_index": 33}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Hydrocerussite forms scrutinyite to a larger extent than plattenrite, whereas cerussite turns mainly into plattenrite with small contents of scrutinyite.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "cerussite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 81, "resolver_kept": 3, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 2, "lexical_scanned": 2314, "lexical_candidates": 217, "lexical_kept": 5, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/2fa5016f36a3a3c1d34d4975cd4edca32783a320.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[Sulfate]--> PbSO4", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nFocused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate).", "ref_list": ["AZE S, VALLET JM, BARONNET A, et al. The fading of red lead pigment in wall paintings: tracking the physico-chemical transformations by means of complementary micro-analysis techniques [J/OL]. European Journal of Mineralogy, 2006. DOI: 10.1127/0935-1221/2006/0018-0835."], "ref_snippets": [{"text": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate).", "score": null, "snippets": [{"text": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate).", "score": null, "metadata": {"page": 1, "chunk_index": 0, "year": "2006", "fulltext_url": "https://content5.schweizerbart.de//download/9Q9fZcGIB42OwmxuPRKWLBOFU34YY6", "doi": "10.1127/0935-1221/2006/0018-0835", "journal": "European Journal of Mineralogy", "source_file": "The_fading_of_red_lead_pigment_in_wall_paintings_tracking_the_physico-chemical_transformat_0761b14aeacf.pdf", "ingest_kind": "pdf_fulltext", "source": "The_fading_of_red_lead_pigment_in_wall_paintings_tracking_the_physico-chemical_transformat_0761b14aeacf.pdf", "title": "The fading of red lead pigment in wall paintings: tracking the physico-chemical transformations by means of complementary micro-analysis techniques", "authors": [{"family": "Aze", "given": "Sébastien"}, {"family": "Vallet", "given": "Jean-Marc"}, {"family": "Baronnet", "given": "Alain"}, {"family": "Grauby", "given": "Olivier"}], "volume": "18", "issue": "6", "pages": "835-843", "url": "https://doi.org/10.1127/0935-1221/2006/0018-0835"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "resolver"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "PbSO4", "condition": "Sulfate", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "lead sulphate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 14, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 201, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/315008dc660704791be195b5abdd70c026cdab2c.json

@@ -0,0 +1 @@
+{"root_material": "C16​H10​N2​O2​", "path_str": "C16​H10​N2​O2​ --[Uv]--> C8​H5​N​O2​ --[Uv]--> C8​H5​N​O3​ --[Uv]--> C7​H7​N​O2​", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nVerification of the reaction mechanism by experiment As shown in Fig. 2b, when the air was exposed to indigo at a constant flow rate for 2.5 h the colour of indigo barely changed and was subsequently dissolved in DMSO and Fig. 6 a HPLC of indigo before and after reaction with O3 and HPLC of isatin; b Fluorescence spectrum of indigo before and after reaction with O3 and fluorescence spectrum of isatin\n\n[1] Evidence classification: edge 1: direct\nPage 8 of 12Li et al. Heritage Science (2023) 11:50 the O atoms on the C atom, the O atoms at the ends of the O3 molecule first combine with the C=C of the indigo molecule to form a five-membered ring, and O1 of the original O3 molecule breaks with O2, followed by a C–C break to form an isatin molecule and criegee radical, as shown in Additional file 1: Figure S6a.\n\n[2] Evidence classification: edge 1: direct\nPage 9 of 12 Li et al. Heritage Science (2023) 11:50 Fig. 7 a Mass spectra of indigo molecules detected in indigo standard solution; b Mass spectra of residual indigo molecules detected in indigo solution after reaction with O3; c Mass spectra of product isatin molecules detected in indigo solution after reaction with O3; d Mass spectra of product C8H6NO3 detected in indigo solution after reaction with O3; e Mass spectra of product molecules C16H10N2O3 detected in indigo solution after reaction with O3", "ref_list": ["A study of the oxidation mechanism of the organic pigment indigo in grottoes murals by ozone under dark conditions [J/OL]. Heritage Science, 2023:8. DOI: 10.1186/s40494-023-00887-7. (bibliographic metadata partially available)", "A study of the oxidation mechanism of the organic pigment indigo in grottoes murals by ozone under dark conditions [J/OL]. Heritage Science, 2023:9. DOI: 10.1186/s40494-023-00887-7. (bibliographic metadata partially available)", "DELGADO MC. El índigo en la pintura de caballete novohispana: mecanismos de deterioro [J/OL]. Intervención, Revista Internacional de Conservación, Restauración y Museología, 2019. DOI: 10.30763/intervencion.2019.19.206."], "ref_snippets": [{"text": "Verification of the reaction mechanism by experiment As shown in Fig. 2b, when the air was exposed to indigo at a constant flow rate for 2.5 h the colour of indigo barely changed and was subsequently dissolved in DMSO and Fig. 6 a HPLC of indigo before and after reaction with O3 and HPLC of isatin; b Fluorescence spectrum of indigo before and after reaction with O3 and fluorescence spectrum of isatin\nPage 8 of 12Li et al. Heritage Science (2023) 11:50 the O atoms on the C atom, the O atoms at the ends of the O3 molecule first combine with the C=C of the indigo molecule to form a five-membered ring, and O1 of the original O3 molecule breaks with O2, followed by a C–C break to form an isatin molecule and criegee radical, as shown in Additional file 1: Figure S6a.", "score": 0.43492257595062256, "snippets": [{"text": "Verification of the reaction mechanism by experiment As shown in Fig. 2b, when the air was exposed to indigo at a constant flow rate for 2.5 h the colour of indigo barely changed and was subsequently dissolved in DMSO and Fig. 6 a HPLC of indigo before and after reaction with O3 and HPLC of isatin; b Fluorescence spectrum of indigo before and after reaction with O3 and fluorescence spectrum of isatin", "score": 0.43492257595062256, "metadata": {"source_file": "Indigo oxidation mechanism in grottoes murals by ozone", "chunk_index": "24", "year": "2023", "doi": "10.1186/s40494-023-00887-7", "source": "Indigo oxidation mechanism in grottoes murals by ozone", "page": "8", "journal": "Heritage Science", "ingest_kind": "pdf_fulltext", "title": "A study of the oxidation mechanism of the organic pigment indigo in grottoes murals by ozone under dark conditions"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "C16H10N2O2", "product": "C8H5NO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Verification of the reaction mechanism by experiment As shown in Fig. 2b, when the air was exposed to indigo at a constant flow rate for 2.5 h the colour of indigo barely changed and was subsequently dissolved in DMSO and Fig. 6 a HPLC of indigo before and after reaction with O3 and HPLC of isatin; b Fluorescence spectrum of indigo before and after reaction with O3 and fluorescence spectrum of isatin", "reactant_match": "alias", "product_match": "alias", "reactant_span": "indigo", "product_span": "isatin", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Page 8 of 12Li et al. Heritage Science (2023) 11:50 the O atoms on the C atom, the O atoms at the ends of the O3 molecule first combine with the C=C of the indigo molecule to form a five-membered ring, and O1 of the original O3 molecule breaks with O2, followed by a C–C break to form an isatin molecule and criegee radical, as shown in Additional file 1: Figure S6a.", "score": 0.45905983448028564, "metadata": {"source": "Indigo oxidation mechanism in grottoes murals by ozone", "chunk_index": "22", "page": "8", "title": "A study of the oxidation mechanism of the organic pigment indigo in grottoes murals by ozone under dark conditions", "doi": "10.1186/s40494-023-00887-7", "year": "2023", "ingest_kind": "pdf_fulltext", "journal": "Heritage Science", "source_file": "Indigo oxidation mechanism in grottoes murals by ozone"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "C16H10N2O2", "product": "C8H5NO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Page 8 of 12Li et al. Heritage Science (2023) 11:50 the O atoms on the C atom, the O atoms at the ends of the O3 molecule first combine with the C=C of the indigo molecule to form a five-membered ring, and O1 of the original O3 molecule breaks with O2, followed by a C–C break to form an isatin molecule and criegee radical, as shown in Additional file 1: Figure S6a.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "indigo", "product_span": "isatin", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Page 9 of 12 Li et al. Heritage Science (2023) 11:50 Fig. 7 a Mass spectra of indigo molecules detected in indigo standard solution; b Mass spectra of residual indigo molecules detected in indigo solution after reaction with O3; c Mass spectra of product isatin molecules detected in indigo solution after reaction with O3; d Mass spectra of product C8H6NO3 detected in indigo solution after reaction with O3; e Mass spectra of product molecules C16H10N2O3 detected in indigo solution after reaction with O3", "score": null, "snippets": [{"text": "Page 9 of 12 Li et al. Heritage Science (2023) 11:50 Fig. 7 a Mass spectra of indigo molecules detected in indigo standard solution; b Mass spectra of residual indigo molecules detected in indigo solution after reaction with O3; c Mass spectra of product isatin molecules detected in indigo solution after reaction with O3; d Mass spectra of product C8H6NO3 detected in indigo solution after reaction with O3; e Mass spectra of product molecules C16H10N2O3 detected in indigo solution after reaction with O3", "score": null, "metadata": {"ingest_kind": "pdf_fulltext", "chunk_index": "25", "year": "2023", "doi": "10.1186/s40494-023-00887-7", "page": "9", "source": "Indigo oxidation mechanism in grottoes murals by ozone", "title": "A study of the oxidation mechanism of the organic pigment indigo in grottoes murals by ozone under dark conditions", "journal": "Heritage Science", "source_file": "Indigo oxidation mechanism in grottoes murals by ozone"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "C16H10N2O2", "product": "C8H5NO2", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Page 9 of 12 Li et al. Heritage Science (2023) 11:50 Fig. 7 a Mass spectra of indigo molecules detected in indigo standard solution; b Mass spectra of residual indigo molecules detected in indigo solution after reaction with O3; c Mass spectra of product isatin molecules detected in indigo solution after reaction with O3; d Mass spectra of product C8H6NO3 detected in indigo solution after reaction with O3; e Mass spectra of product molecules C16H10N2O3 detected in indigo solution after reaction with O3", "reactant_match": "alias", "product_match": "alias", "reactant_span": "indigo", "product_span": "isatin", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}], "related_context": [], "retrieval_trace": {"query_count": 29, "dense_candidates": 580, "dense_kept": 2, "resolver_scanned": 2314, "resolver_candidates": 46, "resolver_kept": 3, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 169, "lexical_kept": 3, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/327cc7f75d78af10323c9684d1bf63a58c2bb828.json

@@ -0,0 +1 @@
+{"root_material": "As4S4", "path_str": "As4S4 --[5000lux+1.65W/m2+30℃+60%RH]--> p-As4S4", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["JOVANOVSKI G, MAKRESKI P. Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization [J/OL]. ChemTexts, 2020. DOI: 10.1007/s40828-019-0100-9."], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [{"source": "Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization [J/OL]. Heritage Science, 2024. DOI: 10.1186/s40494-024-01350-x. (bibliographic metadata partially available)", "snippet": "elemental analysis. With these methods, it is not always possible to distinguish arsenic-bearing minerals from synthetic arsenic sulfides and secondary phases. As for the latter, the degradation of realgar into pararealgar was not described in detail until 1996. Before this date, the historical sources mention that light exposed realgar forms orpiment, which led to misinterpretation and up until almost 30 years ago, the friable yellow pararealgar generally was identified as orpiment [71, 72]. It is important to realize that to differentiate between the three classes of arsenic compounds, additional analytical methods of high specificity such as Raman spectroscopy and X-ray powder diffraction are essential. In this article, two types of arsenic sulfide pigments discovered in Rembrandt’s oeuvre are presented: (regular) pararealgar, which is yellow, and a semi- amorphous variant that is orange to red. The historic use, complexity of identification and interpretation of arsenic sulfides is studied in relevant historical sources to explain their use by Rembrandt. The presence of arsenic sulfides in The Night Watch was first detected by non-invasive imaging when the entire surface of the painting was scanned with macroscopic X-ray fluorescence imaging spectroscopy (MA-XRF) (Fig. 1c). Subsequent examination of the paint surface with stereomicroscopy revealed small areas of bright orange paint (Fig. 1d) in several areas at the surface and in the underpainting of the embroidery of Willem van Ruytenburch’s buff coat (the figure dressed in yellow in the mi", "retrieval_origin": "resolver", "match": {"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "5000lux+1.65W/m2+30℃+60%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.88, "window": "Before this date, the historical sources mention that light exposed realgar forms orpiment, which led to misinterpretation and up until almost 30 years ago, the friable yellow pararealgar generally was identified as orpiment [71, 72].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "partial", "provenance_level": "unspecified", "reasons": ["condition_partial"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "KEUNE K, MASS J, MEHTA A, et al. Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues [J/OL]. Heritage Science, 2016. DOI: 10.1186/s40494-016-0078-1.", "snippet": "tue and vice, wisdom and strength, and mars and venus united by love. In: Metropolitan museum studies in art, science, and technology; 2010. p 83–108. 5. Keune K, Mass J, Meirer F, Pottasch C, van Loon A, Hull A, Church J, Pouyet E, Cotte M, Mehta A. Tracking the transformation and transport of arsenic sulfide pigments in paints: synchrotron-based X-ray micro-analysis. J Anal At Spectrom. 2015;30:813–27. 6. Douglass DL, Shing C, Wang G. The light-induced alteration of realgar to pararealgar. American Mineralolist. 1992;77:1266–74. 7. Ballirano P , Maras A. Preliminary results on the ligh-induced alteration of realgar: kinetics of the process. Plinius. 2002;28:35–6. 8. Mass J. Personal observations; 2015. 9. Trentelman K, Stodulski L, Pavlosky M. Characterization of pararealgar and other light-induced transformation products from realgar by Raman microspectroscopy. Anal Chem. 1996;68:1755–61. 10. Rötter C, Grundmann G, Richter M, van Loon A, Keune K, Boersma A, Rapp K. The occurrence of artificial orpiment (dry process) in northern European painting and polychromy and evidence in historical sources. In: Schuller M, Emmerling E, Nerdinger W, Verlag Anton Siegl, editors. Auripigment/Orpiment: Studien zu dem Mineral und den künstlichten Produkten. Fachbuchhandlung GmbH. München; 2007. 11. van Loon A: Colour changes and chemical reactivity in seventeenth-cen- tury oil paintings. In: Ph.D. Thesis. University of Amsterdam, Molart Series (14), AMOLF: Amsterdam; 2008. 12. Sheldon L, Woodcock S, Wallert A. Orpiment overlooked-expect the", "retrieval_origin": "resolver", "match": {"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "5000lux+1.65W/m2+30℃+60%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.88, "window": "J Anal At Spectrom. 2015;30:813–27. 6. Douglass DL, Shing C, Wang G. The light-induced alteration of realgar to pararealgar.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "partial", "provenance_level": "unspecified", "reasons": ["condition_partial"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "JOVANOVSKI G, MAKRESKI P. Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization [J/OL]. ChemTexts, 2020. DOI: 10.1007/s40828-019-0100-9.", "snippet": "This lecture text is aimed at teaching some insight into phase transitions of minerals. It summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (\\(\\alpha\\)-As\\({}_{4}\\)S\\({}_{4}\\)) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy. The process of transformation takes place in four steps. The initiating photoreaction step requires oxygen and thereby the intermediate azonite (As\\({}_{4}\\)S\\({}_{5}\\)) and arsenolite (As\\({}_{2}\\)O\\({}_{3}\\)) are obtained (step 1). The process continues through a set of cyclic reactions in which the sulfur atom released by the decomposition of As\\({}_{4}\\)S\\({}_{5}\\) (step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "5000lux+1.65W/m2+30℃+60%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.8, "window": "The process continues through a set of cyclic reactions in which the sulfur atom released by the decomposition of As4S5 (step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "unstated", "provenance_level": "unspecified", "reasons": ["condition_unstated"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 157, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 157, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/3549858031691aa565f37f70da789e3056a80cf3.json

@@ -0,0 +1 @@
+{"root_material": "2PbCO3·Pb(OH)2", "path_str": "2PbCO3·Pb(OH)2 --[Fresco]--> β-PbO --[Fresco]--> Pb3O4", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nUpon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.\n\n[1] Evidence classification: edge 1: direct, pathway endpoints 2PbCO3·Pb(OH)2 -> Pb3O4: direct\nUnder a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "ref_list": ["VAGNINI M, VIVANI R, SGAMELLOTTI A, et al. Blackening of lead white: Study of model paintings [J/OL]. Journal of Raman Spectroscopy, 2020. DOI: 10.1002/jrs.5879."], "ref_snippets": [{"text": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.\nUnder a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "score": null, "snippets": [{"text": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.", "score": null, "metadata": {"source": "markdown_output/Blackening of lead white: Study of model paintings.md", "chunk_index": 21, "title": "Blackening of lead white: Study of model paintings", "doi": "10.1002/jrs.5879", "ingest_kind": "existing_chroma", "source_file": "Blackening of lead white: Study of model paintings.md", "journal": "Journal of Raman Spectroscopy", "year": "2020", "authors": [{"family": "Vagnini", "given": "Manuela"}, {"family": "Vivani", "given": "Riccardo"}, {"family": "Sgamellotti", "given": "Antonio"}, {"family": "Miliani", "given": "Costanza"}], "volume": "51", "issue": "7", "pages": "1118-1126", "url": "https://doi.org/10.1002/jrs.5879"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "beta-PbO", "condition": "Fresco", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "massicot", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "score": null, "metadata": {"title": "Blackening of lead white: Study of model paintings", "journal": "Journal of Raman Spectroscopy", "year": "2020", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "ingest_kind": "existing_chroma", "chunk_index": 35, "source_file": "Blackening of lead white: Study of model paintings.md", "doi": "10.1002/jrs.5879", "authors": [{"family": "Vagnini", "given": "Manuela"}, {"family": "Vivani", "given": "Riccardo"}, {"family": "Sgamellotti", "given": "Antonio"}, {"family": "Miliani", "given": "Costanza"}], "volume": "51", "issue": "7", "pages": "1118-1126", "url": "https://doi.org/10.1002/jrs.5879"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "2PbCO3·Pb(OH)2", "product": "beta-PbO", "condition": "Fresco", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "litharge", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "2PbCO3·Pb(OH)2", "product": "Pb3O4", "condition": "Fresco", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "hydrocerussite", "product_span": "Pb3O4", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 111, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 284, "lexical_kept": 2, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/368bc0cf6e6464b50ef710aa2729551af6a85ebb.json

@@ -0,0 +1 @@
+{"root_material": "As4S4", "path_str": "As4S4 --[Uv]--> As2O3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nArsenolite is known to be a light-induced degradation product of orpiment and pararealgar, which explains why it is mainly present close to the surface and in the crack of the paint sample, where the highest levels of light exposure can be expected.\n\n[2] Evidence classification: edge 1: direct\nHowever, arsenic oxide is also an expected degradation product of pararealgar itself [58].\n\n[3] Evidence classification: edge 1: direct\nExposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].\n\n[4] Evidence classification: edge 1: direct\nThe highest degradation efficiency is in the green part of the visible light spectrum (530–560 nm) [6]. In the first step of light induced degradation, realgar undergoes poly - morphism and becomes friable and bright yellow, (As xSy, para-realgar) and subsequently degrades further to a white phase (As2O3, arsenolite). The photo-oxidation of orpiment, on the other hand, results directly in a white product (arsenolite), often appearing as a dirty/off white color or an ocherous material because of the presence of an overlying varnish [6, 7]. In objects painted with large fields of orpiment, the degradation is often not uniform, resulting in a mix of ivory to ochre yellow [8]. The deg - radation products of arsenic sulfide pigments have been observed and identified in painted works of art by visual observation, µRaman spectroscopy, and X-ray diffraction [9–18].", "ref_list": ["Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization [J/OL]. Heritage Science, 2024. DOI: 10.1186/s40494-024-01350-x. (bibliographic metadata partially available)", "VERMEULEN M, SAVERWYNS S, COUDRAY A, et al. Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments [J/OL]. Dyes and Pigments, 2018. DOI: 10.1016/j.dyepig.2017.10.009.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:16. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "KEUNE K, MASS J, MEHTA A, et al. Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues [J/OL]. Heritage Science, 2016. DOI: 10.1186/s40494-016-0078-1.", "JOVANOVSKI G, MAKRESKI P. Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization [J/OL]. ChemTexts, 2020. DOI: 10.1007/s40828-019-0100-9."], "ref_snippets": [{"text": "Arsenolite is known to be a light-induced degradation product of orpiment and pararealgar, which explains why it is mainly present close to the surface and in the crack of the paint sample, where the highest levels of light exposure can be expected.", "score": 0.49438923597335815, "snippets": [{"text": "Arsenolite is known to be a light-induced degradation product of orpiment and pararealgar, which explains why it is mainly present close to the surface and in the crack of the paint sample, where the highest levels of light exposure can be expected.", "score": 0.49438923597335815, "metadata": {"year": "2024", "journal": "Heritage Science", "doi": "10.1186/s40494-024-01350-x", "source": "pdf_direct/s40494-024-01350-x", "ingest_kind": "pdf_direct", "title": "Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization", "chunk_index": 22, "source_file": "s40494-024-01350-x.pdf"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "As2O3", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Arsenolite is known to be a light-induced degradation product of orpiment and pararealgar, which explains why it is mainly present close to the surface and in the crack of the paint sample, where the highest levels of light exposure can be expected.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "pararealgar", "product_span": "arsenolite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "However, arsenic oxide is also an expected degradation product of pararealgar itself [58].", "score": null, "snippets": [{"text": "However, arsenic oxide is also an expected degradation product of pararealgar itself [58].", "score": null, "metadata": {"journal": "Dyes and Pigments", "source_file": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments.md", "title": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments", "chunk_index": 24, "ingest_kind": "pdf_reextract", "year": "2018", "doi": "10.1016/j.dyepig.2017.10.009", "source": "pdf_reextract/雄黄"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "As2O3", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "However, arsenic oxide is also an expected degradation product of pararealgar itself [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "pararealgar", "product_span": "arsenic oxide", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Exposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].", "score": null, "snippets": [{"text": "Exposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].", "score": null, "metadata": {"source": "On the stability of mediaeval inorganic pigments - a review", "year": "2017", "page": "16", "ingest_kind": "pdf_fulltext", "chunk_index": "53", "source_file": "On the stability of mediaeval inorganic pigments - a review", "doi": "10.1186/s40494-017-0125-6", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "journal": "Heritage Science"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "As2O3", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Exposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "arsenic trioxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The highest degradation efficiency is in the green part of the visible light spectrum (530–560 nm) [6]. In the first step of light induced degradation, realgar undergoes poly - morphism and becomes friable and bright yellow, (As xSy, para-realgar) and subsequently degrades further to a white phase (As2O3, arsenolite). The photo-oxidation of orpiment, on the other hand, results directly in a white product (arsenolite), often appearing as a dirty/off white color or an ocherous material because of the presence of an overlying varnish [6, 7]. In objects painted with large fields of orpiment, the degradation is often not uniform, resulting in a mix of ivory to ochre yellow [8]. The deg - radation products of arsenic sulfide pigments have been observed and identified in painted works of art by visual observation, µRaman spectroscopy, and X-ray diffraction [9–18].", "score": null, "snippets": [{"text": "The highest degradation efficiency is in the green part of the visible light spectrum (530–560 nm) [6]. In the first step of light induced degradation, realgar undergoes poly - morphism and becomes friable and bright yellow, (As xSy, para-realgar) and subsequently degrades further to a white phase (As2O3, arsenolite). The photo-oxidation of orpiment, on the other hand, results directly in a white product (arsenolite), often appearing as a dirty/off white color or an ocherous material because of the presence of an overlying varnish [6, 7]. In objects painted with large fields of orpiment, the degradation is often not uniform, resulting in a mix of ivory to ochre yellow [8]. The deg - radation products of arsenic sulfide pigments have been observed and identified in painted works of art by visual observation, µRaman spectroscopy, and X-ray diffraction [9–18].", "score": null, "metadata": {"source_file": "s40494-016-0078-1.pdf", "journal": "Heritage Science", "year": "2016", "ingest_kind": "pdf_direct", "chunk_index": 5, "title": "Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues", "source": "pdf_direct/s40494-016-0078-1", "doi": "10.1186/s40494-016-0078-1"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "As2O3", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The highest degradation efficiency is in the green part of the visible light spectrum (530–560 nm) [6]. In the first step of light induced degradation, realgar undergoes poly - morphism and becomes friable and bright yellow, (As xSy, para-realgar) and subsequently degrades further to a white phase (As2O3, arsenolite). The photo-oxidation of orpiment, on the other hand, results directly in a white product (arsenolite), often appearing as a dirty/off white color or an ocherous material because of the presence of an overlying varnish [6, 7]. In objects painted with large fields of orpiment, the degradation is often not uniform, resulting in a mix of ivory to ochre yellow [8]. The deg - radation products of arsenic sulfide pigments have been observed and identified in painted works of art by visual observation, µRaman spectroscopy, and X-ray diffraction [9–18].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "arsenolite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 30, "resolver_kept": 4, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 165, "lexical_kept": 4, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/372ea2fcc6d3322eefb7278dfa73e04a4a444831.json

@@ -0,0 +1 @@
+{"root_material": "CaCO3", "path_str": "CaCO3 --[Sulfate]--> CaSO4·2H2​O", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nIt is formed by the transformation of calcite (CaCO3) contained in the joint mortars and renders into gypsum by dry or wet deposition (acid rain) of sulfur dioxide (SO2).", "ref_list": ["KILIAN R, BORGATTA L, WENDLER E. Investigation of the deterioration mechanisms induced by moisture and soluble salts in the necropolis of Porta Nocera, Pompeii (Italy) [J/OL]. Heritage Science, 2023. DOI: 10.1186/s40494-023-00900-z."], "ref_snippets": [{"text": "It is formed by the transformation of calcite (CaCO3) contained in the joint mortars and renders into gypsum by dry or wet deposition (acid rain) of sulfur dioxide (SO2).", "score": 0.45167970657348633, "snippets": [{"text": "It is formed by the transformation of calcite (CaCO3) contained in the joint mortars and renders into gypsum by dry or wet deposition (acid rain) of sulfur dioxide (SO2).", "score": 0.45167970657348633, "metadata": {"title": "Investigation of the deterioration mechanisms induced by moisture and soluble salts in the necropolis of Porta Nocera, Pompeii (Italy)", "doi": "10.1186/s40494-023-00900-z", "journal": "Heritage Science", "ingest_kind": "existing_chroma", "chunk_index": 54, "source_file": "Investigation of the deterioration  mechanisms induced by moisture and soluble  salts in the necropolis of Porta Nocera, Pompeii  (Italy).md", "year": "2023", "source": "markdown_output/Investigation of the deterioration  mechanisms induced by moisture and soluble  salts in the necropolis of Porta Nocera, Pompeii  (Italy).md", "authors": [{"family": "Kilian", "given": "Ralf"}, {"family": "Borgatta", "given": "Léo"}, {"family": "Wendler", "given": "Eberhard"}], "volume": "11", "issue": "1", "article_number": "72", "url": "https://doi.org/10.1186/s40494-023-00900-z"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "CaCO3", "product": "CaSO4·2H2O", "condition": "Sulfate", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "It is formed by the transformation of calcite (CaCO3) contained in the joint mortars and renders into gypsum by dry or wet deposition (acid rain) of sulfur dioxide (SO2).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "calcite", "product_span": "gypsum", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 44, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 136, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/39b76ae8c17227cad4fd0036c8d6b409d2052b68.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[tung_oil+Uv]--> 2PbCO3·Pb(OH)2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nDuring UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "ref_list": ["ZHAO Y, WANG J, PAN A, et al. Degradation of red lead pigment in the oil painting during UV aging [J/OL]. Color Research & Application, 2019. DOI: 10.1002/col.22386."], "ref_snippets": [{"text": "During UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "score": 0.33767104148864746, "snippets": [{"text": "During UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "score": 0.33767104148864746, "metadata": {"chunk_index": 3, "title": "Degradation of red lead pigment in the oil painting during UV aging", "ingest_kind": "existing_chroma", "source_file": "Degradation of red lead pigment in the oil painting during UV aging.md", "source": "markdown_output/Degradation of red lead pigment in the oil painting during UV aging.md", "year": "2019", "journal": "Color Research & Application", "doi": "10.1002/col.22386", "authors": [{"family": "Zhao", "given": "Yanrui"}, {"family": "Wang", "given": "Jianli"}, {"family": "Pan", "given": "Aizhao"}, {"family": "He", "given": "Ling"}, {"family": "Simon", "given": "Stefan"}], "volume": "44", "issue": "5", "pages": "790-797", "url": "https://doi.org/10.1002/col.22386"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "2PbCO3·Pb(OH)2", "condition": "tungoil+Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "During UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "2PbCO3Pb(OH)2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 60, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 260, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/3a0ac03db3e07ca86c7be3dfa0ed71767235cb65.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv]--> β-HgS", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\n### Vermilion The colour change of the Vermilion pigment (red to black) is the result of the following reaction: \\mathrm{HgSCinnabar}\\xrightarrow{laser}\\mathrm{HgSMetacinabar} The Cinnabar-Vermilion is a red material with a hexagonal crystal structure, Metacinnabar-Vermilion is black or grey-black obtaining a metallic sheet and a cubic structure.\n\n[2] Evidence classification: edge 1: direct\nThe small relative concentration of sulfur still present in the acids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.\n\n[2] Evidence classification: edge 1: direct\nacids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.\n\n[3] Evidence classification: edge 1: direct\nFigure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1}\n\n[3] Evidence classification: edge 1: direct\nFigure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].\n\n[4] Evidence classification: edge 1: direct\nThe origins of this darkening degradation are not clearly identified yet and remain a major issue for curators. In the specific case of cinnabar (HgS)-based red pigment, a photoinduced conversion into black metacinnabar is usually suspected.", "ref_list": ["CHAPPÉ M, HILDENHAGEN J, DICKMANN K, et al. Laser irradiation of medieval pigments at IR, VIS and UV wavelengths [J/OL]. Journal of Cultural Heritage, 2003. DOI: 10.1016/s1296-2074(02)01206-2.", "KEUNE K, BOON JJ. Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings [J/OL]. Analytical Chemistry, 2005. DOI: 10.1021/ac048158f.", "ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "COTTE M, SUSINI J, METRICH N, et al. Blackening of Pompeian Cinnabar Paintings: X-ray Microspectroscopy Analysis [J/OL]. Analytical Chemistry, 2006. DOI: 10.1021/ac0612224."], "ref_snippets": [{"text": "### Vermilion The colour change of the Vermilion pigment (red to black) is the result of the following reaction: \\mathrm{HgSCinnabar}\\xrightarrow{laser}\\mathrm{HgSMetacinabar} The Cinnabar-Vermilion is a red material with a hexagonal crystal structure, Metacinnabar-Vermilion is black or grey-black obtaining a metallic sheet and a cubic structure.", "score": null, "snippets": [{"text": "### Vermilion The colour change of the Vermilion pigment (red to black) is the result of the following reaction: \\mathrm{HgSCinnabar}\\xrightarrow{laser}\\mathrm{HgSMetacinabar} The Cinnabar-Vermilion is a red material with a hexagonal crystal structure, Metacinnabar-Vermilion is black or grey-black obtaining a metallic sheet and a cubic structure.", "score": null, "metadata": {"title": "Laser irradiation of medieval pigments at IR, VIS and UV wavelengths", "year": "2003", "source_file": "Laser irradiation of medieval pigments at IR, VIS and UV wavelengths.md", "doi": "10.1016/s1296-2074(02)01206-2", "journal": "Journal of Cultural Heritage", "source": "markdown_output/Laser irradiation of medieval pigments at IR, VIS and UV wavelengths.md", "chunk_index": 14, "ingest_kind": "existing_chroma", "authors": [{"family": "Chappé", "given": "M"}, {"family": "Hildenhagen", "given": "J"}, {"family": "Dickmann", "given": "K"}, {"family": "Bredol", "given": "M"}], "volume": "4", "pages": "264-270", "url": "https://doi.org/10.1016/s1296-2074(02)01206-2"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "beta-HgS", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "### Vermilion The colour change of the Vermilion pigment (red to black) is the result of the following reaction: \\mathrm{HgSCinnabar}\\xrightarrow{laser}\\mathrm{HgSMetacinabar} The Cinnabar-Vermilion is a red material with a hexagonal crystal structure, Metacinnabar-Vermilion is black or grey-black obtaining a metallic sheet and a cubic structure.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "metacinnabar", "relation_basis": "explicit_equation", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The small relative concentration of sulfur still present in the acids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.\nacids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.", "score": null, "snippets": [{"text": "The small relative concentration of sulfur still present in the acids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.", "score": null, "metadata": {"source": "markdown_output/Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "chunk_index": 39, "journal": "Analytical Chemistry", "doi": "10.1021/ac048158f", "year": "2005", "ingest_kind": "existing_chroma", "title": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings", "source_file": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "beta-HgS", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The small relative concentration of sulfur still present in the acids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "metacinnabar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "acids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.", "score": null, "metadata": {"journal": "Analytical Chemistry", "chunk_index": 40, "year": "2005", "title": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings", "doi": "10.1021/ac048158f", "source": "markdown_output/Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "ingest_kind": "existing_chroma", "source_file": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "beta-HgS", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "acids.[21] Since the sulfur is lost from the particle, it is inferred that a conversion of vermilion to meta-cinnabar is unlikely. The small relative concentration of sulfur still present in the particles is ascribed to intact residual intact vermilion. XRD measurements performed on reconstructions and other paint samples elsewhere by other authors support this conclusion.[2, 47, 39] It is shown that vermilion is still present in the XRD spectra of the blackened vermilion as is deduced from the decreased intensity of the XRD patterns of vermilion. No black meta-cinnabar was shown in the XRD spectra. Chlorine plays a dominant role in the light-induced blackening phenomenon, as already suggested in the literature.[7, 9] The much more sensitive surface technique of SIMS demonstrates, in contrast to the EDX results, that chloride is present inside the vermilion particles of both MH 251/26 and HSTB 34/2.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "metacinnabar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Figure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1}\nFigure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": null, "snippets": [{"text": "Figure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1}", "score": null, "metadata": {"title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 42, "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "journal": "Communications Chemistry", "year": "2021", "doi": "10.1038/s42004-021-00610-2", "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "beta-HgS", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Figure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1}", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "HgS", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Figure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": null, "metadata": {"year": "2021", "ingest_kind": "existing_chroma", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 43, "journal": "Communications Chemistry", "doi": "10.1038/s42004-021-00610-2"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "beta-HgS", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Figure 6: **FESEM images and XPS spectra of paint mock-ups.** a UV-exposed paint mock-up showing severe binder loss; **b** unaltered paint mock-up showing drying cracks (arrows) and **c** nano- to micrometer-sized mercury droplets (ranging from <100 nm to 1.5 μm, white arrows) on the mock-up surface after UV exposure (insets show EDS spectra of Hg{}^{0} droplet (white arrows) and HgS substrate (yellow arrow)); **d**, **e** depth profiles of 5 2p1/2 and Hg 4f5/2/Hg 4f7/2 upon ion beam etching (etch time in seconds) of cinnabar paint exposed to UV radiation for 2 months. would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "cinnabar", "product_span": "HgS", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The origins of this darkening degradation are not clearly identified yet and remain a major issue for curators. In the specific case of cinnabar (HgS)-based red pigment, a photoinduced conversion into black metacinnabar is usually suspected.", "score": null, "snippets": [{"text": "The origins of this darkening degradation are not clearly identified yet and remain a major issue for curators. In the specific case of cinnabar (HgS)-based red pigment, a photoinduced conversion into black metacinnabar is usually suspected.", "score": null, "metadata": {"source_file": "Blackening of Pompeian Cinnabar Paintings: X-ray Microspectroscopy Analysis.md", "source": "pdf_reextract/朱砂", "year": "2006", "ingest_kind": "pdf_reextract", "chunk_index": 0, "title": "Blackening of Pompeian Cinnabar Paintings: X-ray Microspectroscopy Analysis", "doi": "10.1021/ac0612224", "journal": "Analytical Chemistry"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "beta-HgS", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The origins of this darkening degradation are not clearly identified yet and remain a major issue for curators. In the specific case of cinnabar (HgS)-based red pigment, a photoinduced conversion into black metacinnabar is usually suspected.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "metacinnabar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 7, "dense_candidates": 140, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 217, "resolver_kept": 6, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 217, "lexical_kept": 6, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/3e838c4a5a32c0211343dc8403984e1d713e8964.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[12000lux+1.5W/m2+60℃+90%RH]--> CuCO3·Cu(OH)2", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["CRN source: In-house aging experiment"], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": null}], "related_context": [{"source": "The Use of X-Ray Photoelectron Spectroscopy in Studying Azurite and Malachite as Minerals, Pigments and in Secondary Products on Copper Objects [J/OL]. JOJ Material Science, 2026:11. DOI: 10.19080/jojms.2026.10.555788. (bibliographic metadata partially available)", "snippet": "e, reflecting changes in the coordination environment around copper, from hydroxide-rich to oxide-rich coordination [48]. At 300°C, copper oxide and copper carbonate may coexist, leading to complex XPS spectra, where multiple features may be present. The binding energies for these copper pigments at intermediate stages will be between the main features in the handbook spectra for the pure copper carbonates (934.6eV for copper in azurite and 935.1eV for copper in malachite) and the binding energies for CuO [48]. Further heating to 400°C and above leads to the complete transformation of azurite to tenorite (CuO) or malachite to a combination of tenorite and finally copper(I) oxide in a reducing environment [48]. The Cu 2p 3/2 binding energy for the pure CuO phase is centered at 933.5 to 934.0eV, which is slightly lower than the Cu 2p 3/2 binding energy for the hydroxycarbonate compounds. This is due to the absence of hydroxyl groups and the square planar coordination geometry of the Cu2+ ions in the CuO crystal. This Cu 2p binding energy for CuO at 933.5 to 934.0eV is significantly lower than the Cu2+ peak for malachite at 935.1eV and is even lower than the Cu2+ peak for azurite at 934.6eV [40]. This shows that the removal of the hydroxide ligand during the thermal decomposition leads to a decrease in the Cu 2p binding energy due to a reduction in the electrostatic potential around the Cu2+ ion.", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "12000lux+1.5W/m2+60℃+90%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.8, "window": "Further heating to 400°C and above leads to the complete transformation of azurite to tenorite (CuO) or malachite to a combination of tenorite and finally copper(I) oxide in a reducing environment [48].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "unstated", "provenance_level": "unspecified", "reasons": ["condition_unstated"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "snippet": "mpurities of other minerals such as calcite, haematite (Fe 2O3), goethite α-FeO(OH), quartz (SiO 2), cuprite (Cu 2O), rutile/anatase (TiO 2), and chrysocolle ((Cu,Al)2H2Si2O5(OH)4·nH2O, found with malachite), as well as trace elements including arsenic (As), zirconium (Zr), antimony (Sb), barium (Ba), zinc (Zn), and bismuth (Bi) [28–30]. In fact, the particular mineral composition of natural azurite and malachite varies significantly between artworks produced at different times and places, and may be related to provenance [30]. In addition to the mineralogy, the pigment grain size also influences the color and other superficial physical properties, as demonstrated for azurite in severa l scientific papers [22,31]. These studies also highlighted the importance of the binder (type and co ntent) on the physical properties of the paint. Therefore, the mineralogy, pigment grain size and the type and content of binder should be evaluated to understand the deterioration processes that ta ke place in tempera paints under different decay scenarios. Azurite is formed from cupric-ion-bearing solutions under relatively acid conditions and relatively high carbonate activity, while malachite is a more common form of copper carbonate under ambient conditions [32]. Malachite may pseudomorph after azurite; thus malachite maintains the same external form as the original azurite crystal, but the unit cells of azurite are gradually replaced by those of malachite. In aqueous systems, CO 32− and HCO3− activities (and Cu 2+ activity to a lesser extent) define the stability of bot", "retrieval_origin": "resolver", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "12000lux+1.5W/m2+60℃+90%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.8, "window": "Azurite is formed from cupric-ion-bearing solutions under relatively acid conditions and relatively high carbonate activity, while malachite is a more common form of copper carbonate under ambient conditions [32].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "unstated", "provenance_level": "unspecified", "reasons": ["condition_unstated"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845.", "snippet": "azurite degrades into tenorite on ly below the critical value of 25 µm. To study the chemical alteration of azurite, the pigment has been applied on the plaster o f terracotta samples and analyzed at different pH values by micro-Raman spectroscopy. As opposed to mos t part of the analytical techniques, it can detect the presence of both azurite and tenorite molecules i n the same micro areas, and provides a valuable tool to determine azurite degradation. Copyright  2008 John Wiley & Sons, Ltd. KEYWORDS: azurite; tenorite; laser-induced degradation; pigments alteration INTRODUCTION Azurite is a natural mineral pigment whose chemical composition is basic copper carbonate (2CuCO 3ÐCu(OH)2). It was largely employed in paintings particularly around the middle Ages and the Renaissance, both in Europe and in the East. 1,2 It presents an intense blue color whose tone depends on the grain size, the smaller grains producing a paler blue color. Unfortunately, this pigment suffers from chemical and/or thermal alterations, so that the parts of the artwork containing azurite are usually less resistant than those painted with other pigments. The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite). The conversion into black compounds with formation of copper sulfide 5 (covellite: CuS) or copper oxide 6 (tenorite: CuO) occurs less frequently and is less st", "retrieval_origin": "resolver", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "12000lux+1.5W/m2+60℃+90%RH", "evidence_scope": "edge", "verdict": "related", "score": 0.8, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "unstated", "provenance_level": "unspecified", "reasons": ["condition_unstated"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 148, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 241, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/43d381a5e376f9af2e8b85de32f8f1fa34e9c681.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[tung_oil+Uv]--> 2PbCO3·Pb(OH)2 --[Fresco]--> β-PbO", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nDuring UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.\n\n[2] Evidence classification: pathway endpoints Pb3O4 -> beta-PbO: direct\nthrough successive water and carbonate losses [25] (reactions 1.3 to 1.5). At higher temperature and in oxidizing conditions, litharge was finally converted into minium (Pb3O4, reaction 1.6). \\mathrm{Pb(s)+2CH3COOH\\to Pb(CH3COO)2+H2} \\tag{1} \\mathrm{3Pb(CH3COO)2+12O2\\to 2PbCO3\\cdot Pb(OH)2+10CO2+8H2O} \\tag{2} \\mathrm{2PbCO3\\cdot Pb(OH)2\\to 2PbCO3\\cdot PbO+H2O} \\tag{3} \\mathrm{2PbCO3\\cdot PbO\\to CO2+PbCO3\\cdot 2PbO} \\tag{4} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} According to Brown and Nees [26], litharge may be converted into minium through transitional steps, corresponding to intermediate oxidation states.\n\n[2] Evidence classification: pathway endpoints Pb3O4 -> beta-PbO: direct\nAccording to various authors, minium reduction into massicot is initiated in air over 512{}^{\\circ}C [25], 650{}^{\\circ}C [32], 535{}^{\\circ}C [33], 560{}^{\\circ}C [34].\n\n[3] Evidence classification: pathway endpoints Pb3O4 -> beta-PbO: direct\nThe parameters responsible for the blackening of minium are identified as light [5, 240, 243], including laser light (514 and 488 nm, [215]), the pigment’s composition, and climate. These parameters all contribute to yield a grey discolouration at first, and finally a chocolate brown one [240]. Red lead semiconductor properties are responsi - ble for the reduction of Pb(IV) to Pb(II), and the forma - tion of PbO; the presence of bicarbonate ions (HCO 3 −) promotes then the formation of hydrocerussite and/or cerussite [123, 218, 244].\n\n[3] Evidence classification: pathway endpoints Pb3O4 -> beta-PbO: direct\nThe PbO formed by laser irra - diation can be re-oxidized to minium [142].\n\n[4] Evidence classification: pathway endpoints Pb3O4 -> beta-PbO: direct\nFormation of PbO (which can be re‐oxidised to minium, [142]) [215, 240] Formation of litharge [1, 240] Green Green earths glauconite (K,Na) (Fe 3+,Al,Mg)2 (Si,Al)4O10(OH)2) celadonite (K[(Al,Fe3+), (Fe2+,Mg)] (AlSi3,Si4) O10(OH)2 Browning [74], discolouration of oil layers [75] Green Malachite CuCO 3·Cu(OH)2 Cu acts as a biocide [124].\n\n[5] Evidence classification: pathway endpoints Pb3O4 -> beta-PbO: direct\nThe sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound.\n\n[6] Evidence classification: edge 2: direct\nUpon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.\n\n[6] Evidence classification: edge 2: direct, pathway endpoints Pb3O4 -> beta-PbO: direct\nUnder a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "ref_list": ["ZHAO Y, WANG J, PAN A, et al. Degradation of red lead pigment in the oil painting during UV aging [J/OL]. Color Research & Application, 2019. DOI: 10.1002/col.22386.", "AZE S, VALLET JM, DETALLE V, et al. Chromatic alterations of red lead pigments in artworks: a review [J/OL]. Phase Transitions, 2008. DOI: 10.1080/01411590701514326.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:19. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:8. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "SMITH GD, CLARK RJH. The role of H2S in pigment blackening [J/OL]. Journal of Cultural Heritage, 2002. DOI: 10.1016/s1296-2074(02)01173-1.", "VAGNINI M, VIVANI R, SGAMELLOTTI A, et al. Blackening of lead white: Study of model paintings [J/OL]. Journal of Raman Spectroscopy, 2020. DOI: 10.1002/jrs.5879."], "ref_snippets": [{"text": "During UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "score": 0.337671160697937, "snippets": [{"text": "During UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "score": 0.337671160697937, "metadata": {"chunk_index": 3, "source": "markdown_output/Degradation of red lead pigment in the oil painting during UV aging.md", "journal": "Color Research & Application", "title": "Degradation of red lead pigment in the oil painting during UV aging", "source_file": "Degradation of red lead pigment in the oil painting during UV aging.md", "year": "2019", "ingest_kind": "existing_chroma", "doi": "10.1002/col.22386", "authors": [{"family": "Zhao", "given": "Yanrui"}, {"family": "Wang", "given": "Jianli"}, {"family": "Pan", "given": "Aizhao"}, {"family": "He", "given": "Ling"}, {"family": "Simon", "given": "Stefan"}], "volume": "44", "issue": "5", "pages": "790-797", "url": "https://doi.org/10.1002/col.22386"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "2PbCO3·Pb(OH)2", "condition": "tungoil+Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "During UV aging, the model paint samples' surface is verified gradually from wrinkled surface into nanoscale sheet-like structure and finally a regular hexagonal plate-like crystal structure, showing hexagonal crystals of hydrocerussit 2PbCO3Pb(OH)2. This reveals the interaction between organic tung oil binder and inorganic minium to accelerate the degradation of Pb3O4 pigment. Therefore, the degradation mechanism is deduced as that CO2 and H{}^{+} formed by oxidizing ester/carboxyl groups in tung oil reacts with Pb{}^{2+} to yield the white product of 2PbCO3Pb(OH)2.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "2PbCO3Pb(OH)2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "through successive water and carbonate losses [25] (reactions 1.3 to 1.5). At higher temperature and in oxidizing conditions, litharge was finally converted into minium (Pb3O4, reaction 1.6). \\mathrm{Pb(s)+2CH3COOH\\to Pb(CH3COO)2+H2} \\tag{1} \\mathrm{3Pb(CH3COO)2+12O2\\to 2PbCO3\\cdot Pb(OH)2+10CO2+8H2O} \\tag{2} \\mathrm{2PbCO3\\cdot Pb(OH)2\\to 2PbCO3\\cdot PbO+H2O} \\tag{3} \\mathrm{2PbCO3\\cdot PbO\\to CO2+PbCO3\\cdot 2PbO} \\tag{4} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} According to Brown and Nees [26], litharge may be converted into minium through transitional steps, corresponding to intermediate oxidation states.\nAccording to various authors, minium reduction into massicot is initiated in air over 512{}^{\\circ}C [25], 650{}^{\\circ}C [32], 535{}^{\\circ}C [33], 560{}^{\\circ}C [34].", "score": 0.4271876811981201, "snippets": [{"text": "through successive water and carbonate losses [25] (reactions 1.3 to 1.5). At higher temperature and in oxidizing conditions, litharge was finally converted into minium (Pb3O4, reaction 1.6). \\mathrm{Pb(s)+2CH3COOH\\to Pb(CH3COO)2+H2} \\tag{1} \\mathrm{3Pb(CH3COO)2+12O2\\to 2PbCO3\\cdot Pb(OH)2+10CO2+8H2O} \\tag{2} \\mathrm{2PbCO3\\cdot Pb(OH)2\\to 2PbCO3\\cdot PbO+H2O} \\tag{3} \\mathrm{2PbCO3\\cdot PbO\\to CO2+PbCO3\\cdot 2PbO} \\tag{4} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} According to Brown and Nees [26], litharge may be converted into minium through transitional steps, corresponding to intermediate oxidation states.", "score": 0.4271876811981201, "metadata": {"ingest_kind": "existing_chroma", "doi": "10.1080/01411590701514326", "journal": "Phase Transitions", "title": "Chromatic alterations of red lead pigments in artworks: a review", "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md", "year": "2008", "source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "chunk_index": 7}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "through successive water and carbonate losses [25] (reactions 1.3 to 1.5). At higher temperature and in oxidizing conditions, litharge was finally converted into minium (Pb3O4, reaction 1.6). \\mathrm{Pb(s)+2CH3COOH\\to Pb(CH3COO)2+H2} \\tag{1} \\mathrm{3Pb(CH3COO)2+12O2\\to 2PbCO3\\cdot Pb(OH)2+10CO2+8H2O} \\tag{2} \\mathrm{2PbCO3\\cdot Pb(OH)2\\to 2PbCO3\\cdot PbO+H2O} \\tag{3} \\mathrm{2PbCO3\\cdot PbO\\to CO2+PbCO3\\cdot 2PbO} \\tag{4} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} \\mathrm{PbCO3\\cdot 2PbO\\to CO2+3alpha-PbO} \\tag{5} \\mathrm{3alpha-PbO+1/2O2\\to Pb3O4}. \\tag{6} According to Brown and Nees [26], litharge may be converted into minium through transitional steps, corresponding to intermediate oxidation states.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "minium", "product_span": "litharge", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "According to various authors, minium reduction into massicot is initiated in air over 512{}^{\\circ}C [25], 650{}^{\\circ}C [32], 535{}^{\\circ}C [33], 560{}^{\\circ}C [34].", "score": 0.44352006912231445, "metadata": {"ingest_kind": "existing_chroma", "doi": "10.1080/01411590701514326", "source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "year": "2008", "journal": "Phase Transitions", "chunk_index": 8, "title": "Chromatic alterations of red lead pigments in artworks: a review", "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "According to various authors, minium reduction into massicot is initiated in air over 512{}^{\\circ}C [25], 650{}^{\\circ}C [32], 535{}^{\\circ}C [33], 560{}^{\\circ}C [34].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "minium", "product_span": "massicot", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The parameters responsible for the blackening of minium are identified as light [5, 240, 243], including laser light (514 and 488 nm, [215]), the pigment’s composition, and climate. These parameters all contribute to yield a grey discolouration at first, and finally a chocolate brown one [240]. Red lead semiconductor properties are responsi - ble for the reduction of Pb(IV) to Pb(II), and the forma - tion of PbO; the presence of bicarbonate ions (HCO 3 −) promotes then the formation of hydrocerussite and/or cerussite [123, 218, 244].\nThe PbO formed by laser irra - diation can be re-oxidized to minium [142].", "score": 0.3938230276107788, "snippets": [{"text": "The parameters responsible for the blackening of minium are identified as light [5, 240, 243], including laser light (514 and 488 nm, [215]), the pigment’s composition, and climate. These parameters all contribute to yield a grey discolouration at first, and finally a chocolate brown one [240]. Red lead semiconductor properties are responsi - ble for the reduction of Pb(IV) to Pb(II), and the forma - tion of PbO; the presence of bicarbonate ions (HCO 3 −) promotes then the formation of hydrocerussite and/or cerussite [123, 218, 244].", "score": 0.3938230276107788, "metadata": {"journal": "Heritage Science", "source_file": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext", "doi": "10.1186/s40494-017-0125-6", "chunk_index": "68", "source": "On the stability of mediaeval inorganic pigments - a review", "page": "19", "year": "2017", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The parameters responsible for the blackening of minium are identified as light [5, 240, 243], including laser light (514 and 488 nm, [215]), the pigment’s composition, and climate. These parameters all contribute to yield a grey discolouration at first, and finally a chocolate brown one [240]. Red lead semiconductor properties are responsi - ble for the reduction of Pb(IV) to Pb(II), and the forma - tion of PbO; the presence of bicarbonate ions (HCO 3 −) promotes then the formation of hydrocerussite and/or cerussite [123, 218, 244].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "red lead", "product_span": "PbO", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The PbO formed by laser irra - diation can be re-oxidized to minium [142].", "score": null, "metadata": {"doi": "10.1186/s40494-017-0125-6", "journal": "Heritage Science", "source_file": "On the stability of mediaeval inorganic pigments - a review", "chunk_index": "69", "source": "On the stability of mediaeval inorganic pigments - a review", "year": "2017", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "19", "ingest_kind": "pdf_fulltext"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The PbO formed by laser irra - diation can be re-oxidized to minium [142].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "PbO", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Formation of PbO (which can be re‐oxidised to minium, [142]) [215, 240] Formation of litharge [1, 240] Green Green earths glauconite (K,Na) (Fe 3+,Al,Mg)2 (Si,Al)4O10(OH)2) celadonite (K[(Al,Fe3+), (Fe2+,Mg)] (AlSi3,Si4) O10(OH)2 Browning [74], discolouration of oil layers [75] Green Malachite CuCO 3·Cu(OH)2 Cu acts as a biocide [124].", "score": 0.43764787912368774, "snippets": [{"text": "Formation of PbO (which can be re‐oxidised to minium, [142]) [215, 240] Formation of litharge [1, 240] Green Green earths glauconite (K,Na) (Fe 3+,Al,Mg)2 (Si,Al)4O10(OH)2) celadonite (K[(Al,Fe3+), (Fe2+,Mg)] (AlSi3,Si4) O10(OH)2 Browning [74], discolouration of oil layers [75] Green Malachite CuCO 3·Cu(OH)2 Cu acts as a biocide [124].", "score": 0.43764787912368774, "metadata": {"ingest_kind": "pdf_fulltext", "year": "2017", "source_file": "On the stability of mediaeval inorganic pigments - a review", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "chunk_index": "20", "source": "On the stability of mediaeval inorganic pigments - a review", "page": "8", "doi": "10.1186/s40494-017-0125-6", "journal": "Heritage Science"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Formation of PbO (which can be re‐oxidised to minium, [142]) [215, 240] Formation of litharge [1, 240] Green Green earths glauconite (K,Na) (Fe 3+,Al,Mg)2 (Si,Al)4O10(OH)2) celadonite (K[(Al,Fe3+), (Fe2+,Mg)] (AlSi3,Si4) O10(OH)2 Browning [74], discolouration of oil layers [75] Green Malachite CuCO 3·Cu(OH)2 Cu acts as a biocide [124].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "minium", "product_span": "litharge", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound.", "score": null, "snippets": [{"text": "The sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound.", "score": null, "metadata": {"title": "The role of H2S in pigment blackening", "source": "markdown_output/The role of H2S in pigment blackening.md", "year": "2002", "ingest_kind": "existing_chroma", "journal": "Journal of Cultural Heritage", "doi": "10.1016/s1296-2074(02)01173-1", "source_file": "The role of H2S in pigment blackening.md", "chunk_index": 21}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "red lead", "product_span": "PbO", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.\nUnder a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "score": null, "snippets": [{"text": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.", "score": null, "metadata": {"journal": "Journal of Raman Spectroscopy", "source_file": "Blackening of lead white: Study of model paintings.md", "title": "Blackening of lead white: Study of model paintings", "ingest_kind": "existing_chroma", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "year": "2020", "doi": "10.1002/jrs.5879", "chunk_index": 21}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 2, "reactant": "2PbCO3·Pb(OH)2", "product": "beta-PbO", "condition": "Fresco", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Upon comparison of the Raman spectra recorded at both the beginning and the end of degradation (Figure 3c) with that of pure hydrocerussite, it can be inferred that after 370 days, hydrocerussite is transformed into a mixture of red lead, as the main component, and massicot.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "massicot", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "score": null, "metadata": {"ingest_kind": "existing_chroma", "doi": "10.1002/jrs.5879", "title": "Blackening of lead white: Study of model paintings", "chunk_index": 35, "journal": "Journal of Raman Spectroscopy", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "source_file": "Blackening of lead white: Study of model paintings.md", "year": "2020"}, "evidence_level": "edge_direct", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "2PbCO3·Pb(OH)2", "product": "beta-PbO", "condition": "Fresco", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "hydrocerussite", "product_span": "litharge", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "Pb3O4", "product": "beta-PbO", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Under a fresco conditions, hydrocerussite resulted more reactive than cerussite being the former partially oxidized to red-lead (minimum, Pb3O4 with Pb (II)/Pb (IV)), whereas cerussite simply turns into litharge (alpha-PbO, Pb (II)) without changing its oxidation number.", "reactant_match": "exact", "product_match": "alias", "reactant_span": "Pb3O4", "product_span": "litharge", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 5, "resolver_scanned": 2314, "resolver_candidates": 82, "resolver_kept": 5, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 4, "lexical_scanned": 2314, "lexical_candidates": 352, "lexical_kept": 9, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/44bfe71f0a7866a1e0ec369a1ce417bec8f475a0.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[CO2]--> PbCO3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nFocused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised.\n\n[1] Evidence classification: edge 1: direct\nFocused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised. O 3) phases.", "ref_list": ["AZE S, VALLET JM, BARONNET A, et al. The fading of red lead pigment in wall paintings: tracking the physico-chemical transformations by means of complementary micro-analysis techniques [J/OL]. European Journal of Mineralogy, 2006. DOI: 10.1127/0935-1221/2006/0018-0835."], "ref_snippets": [{"text": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised.\nFocused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised. O 3) phases.", "score": null, "snippets": [{"text": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised.", "score": null, "metadata": {"doi": "10.1127/0935-1221/2006/0018-0835", "page": 1, "journal": "European Journal of Mineralogy", "ingest_kind": "pdf_fulltext", "chunk_index": 0, "title": "The fading of red lead pigment in wall paintings: tracking the physico-chemical transformations by means of complementary micro-analysis techniques", "source": "The_fading_of_red_lead_pigment_in_wall_paintings_tracking_the_physico-chemical_transformat_0761b14aeacf.pdf", "year": "2006", "source_file": "The_fading_of_red_lead_pigment_in_wall_paintings_tracking_the_physico-chemical_transformat_0761b14aeacf.pdf", "fulltext_url": "https://content5.schweizerbart.de//download/9Q9fZcGIB42OwmxuPRKWLBOFU34YY6", "authors": [{"family": "Aze", "given": "Sébastien"}, {"family": "Vallet", "given": "Jean-Marc"}, {"family": "Baronnet", "given": "Alain"}, {"family": "Grauby", "given": "Olivier"}], "volume": "18", "issue": "6", "pages": "835-843", "url": "https://doi.org/10.1127/0935-1221/2006/0018-0835"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "cerussite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised. O 3) phases.", "score": null, "metadata": {"page": 1, "fulltext_url": "https://content5.schweizerbart.de//download/9Q9fZcGIB42OwmxuPRKWLBOFU34YY6", "ingest_kind": "pdf_fulltext", "source_file": "The_fading_of_red_lead_pigment_in_wall_paintings_tracking_the_physico-chemical_transformat_0761b14aeacf.pdf", "title": "The fading of red lead pigment in wall paintings: tracking the physico-chemical transformations by means of complementary micro-analysis techniques", "year": "2006", "journal": "European Journal of Mineralogy", "doi": "10.1127/0935-1221/2006/0018-0835", "chunk_index": 2, "source": "The_fading_of_red_lead_pigment_in_wall_paintings_tracking_the_physico-chemical_transformat_0761b14aeacf.pdf", "authors": [{"family": "Aze", "given": "Sébastien"}, {"family": "Vallet", "given": "Jean-Marc"}, {"family": "Baronnet", "given": "Alain"}, {"family": "Grauby", "given": "Olivier"}], "volume": "18", "issue": "6", "pages": "835-843", "url": "https://doi.org/10.1127/0935-1221/2006/0018-0835"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "PbCO3", "condition": "CO2", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Focused X-ray diffraction patterns of small areas were collected using a highly sensitive detector, revealing the transformation of red lead pigment into both cerussite (lead carbonate) and anglesite (lead sulphate). The distribution of Pb, S, O and Ca elements within the cross-section was estab - lished using electron micro-probe analysis, and correlated to micro-Raman semi-quantitative mappings of minium (Pb3O4), cerus- site (PbCO3), anglesite (PbSO 4) and calcite (CaCO 3) phases. The micro-structural characteristics of each lead-containing phase were investigated by means of scanning electron microscopy observations of the sample cross-section using backscattered elec- tron imaging. The major role of atmospheric pollutants (SO 2, CO2), together with water condensation on such a red pigment fading is emphasised. O 3) phases.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "cerussite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 52, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 201, "lexical_kept": 2, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/44eeb3a4e7a3d103f8dc06f6953119be8b4cb921.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv+Moisture]--> HgSO4", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.\n\n[1] Evidence classification: edge 1: direct\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "ref_list": ["ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "CHAPPÉ M, HILDENHAGEN J, DICKMANN K, et al. Laser irradiation of medieval pigments at IR, VIS and UV wavelengths [J/OL]. Journal of Cultural Heritage, 2003. DOI: 10.1016/s1296-2074(02)01206-2.", "ELERT K, CARDELL C. Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging [J/OL]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019, 216:236-248. DOI: 10.1016/j.saa.2019.03.027."], "ref_snippets": [{"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": 0.49485206604003906, "snippets": [{"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.", "score": 0.49485206604003906, "metadata": {"doi": "10.1038/s42004-021-00610-2", "ingest_kind": "existing_chroma", "journal": "Communications Chemistry", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 43, "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "year": "2021"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "mercury sulfate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": null, "metadata": {"title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "chunk_index": 42, "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "journal": "Communications Chemistry", "year": "2021", "doi": "10.1038/s42004-021-00610-2", "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "mercury sulfate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}], "related_context": [], "retrieval_trace": {"query_count": 11, "dense_candidates": 220, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 15, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 203, "lexical_kept": 2, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/473d69592ad76faef4f245efcf2c9a0fa6bb39bd.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Moisture]--> CuCO3·Cu(OH)2 --[Chloride]--> Cu2Cl(OH)3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 2: direct, pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nThe alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).\n\n[2] Evidence classification: edge 1: direct\nBlack colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.\n\n[2] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].\n\n[4] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nSeveral authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.\n\n[5] Evidence classification: edge 2: direct, pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nMinerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nCavallo, Alteration of azurite into paratacamite at the St.\n\n[6] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nBesides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.\n\n[7] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).\n\n[7] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.\n\n[8] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nHowever, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].\n\n[9] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlteration of azurite into paratacamite at the St.", "ref_list": ["MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845.", "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001.", "PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1.", "VAGNINI M, VIVANI R, VISCUSO E, et al. Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi [J/OL]. Vibrational Spectroscopy, 2018. DOI: 10.1016/j.vibspec.2018.07.006.", "LLUVERAS A, BOULARAND S, ANDREOTTI A, et al. Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR [J/OL]. Applied Physics A, 2010. DOI: 10.1007/s00339-010-5673-5.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:15. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:22. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)"], "ref_snippets": [{"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": 0.4536123275756836, "snippets": [{"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": 0.4536123275756836, "metadata": {"chunk_index": 2, "title": "Raman spectroscopic analysis of azurite blackening", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.1845", "ingest_kind": "pdf_reextract", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "year": "2008"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "clinoatacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "clinoatacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "score": 0.422015905380249, "snippets": [{"text": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "score": 0.422015905380249, "metadata": {"journal": "Minerals", "ingest_kind": "pdf_direct", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "chunk_index": 7, "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "year": "2020", "doi": "10.3390/min10050424", "source": "pdf_direct/min10050424_part2.pdf"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCO3·Cu(OH)2", "condition": "Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups. Part 1 is entitled Accelerated aging of smalt- and lapis lazuli-based paints, while this paper, Part 2, studies azurite- and malachite-based paints, made by mixing one of the pigments with either egg yolk or rabbit glue binder, which were then exposed to SO2 for two months in order to examine the effect of this gas pollutant on the physical -chemical properties of the paints.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "malachite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "score": null, "metadata": {"title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "doi": "10.3390/min10050424", "ingest_kind": "pdf_direct", "journal": "Minerals", "year": "2020", "chunk_index": 5, "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "source": "pdf_direct/min10050424_part2.pdf"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": 0.4175853729248047, "snippets": [{"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": 0.4175853729248047, "metadata": {"ingest_kind": "pdf_fulltext", "journal": "Heritage Science", "source": "On the stability of mediaeval inorganic pigments - a review", "chunk_index": "38", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "year": "2017", "source_file": "On the stability of mediaeval inorganic pigments - a review", "doi": "10.1186/s40494-017-0125-6", "page": "13"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": 0.40759676694869995, "snippets": [{"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": 0.40759676694869995, "metadata": {"source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "source_file": "Degradation of lead-based pigments by salt solutions.md", "journal": "Journal of Cultural Heritage", "ingest_kind": "existing_chroma", "doi": "10.1016/j.culher.2008.11.001", "title": "Degradation of lead-based pigments by salt solutions", "chunk_index": 1, "year": "2009"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\nCavallo, Alteration of azurite into paratacamite at the St.", "score": null, "snippets": [{"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "metadata": {"fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "license": "https://creativecommons.org/licenses/by/4.0", "doi": "10.1007/s00339-024-07954-1", "ingest_kind": "pdf_fulltext", "chunk_index": 22, "source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "year": "2024", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "page": 11, "journal": "Applied Physics A", "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Cavallo, Alteration of azurite into paratacamite at the St.", "score": null, "metadata": {"chunk_index": 43, "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "year": "2024", "license": "https://creativecommons.org/licenses/by/4.0", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "ingest_kind": "pdf_fulltext", "page": 19, "doi": "10.1007/s00339-024-07954-1", "journal": "Applied Physics A", "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Cavallo, Alteration of azurite into paratacamite at the St.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": null, "snippets": [{"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": null, "metadata": {"ingest_kind": "existing_chroma", "source_file": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "doi": "10.1016/j.vibspec.2018.07.006", "source": "markdown_output/Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "title": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi", "journal": "Vibrational Spectroscopy", "year": "2018", "chunk_index": 38}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "score": null, "snippets": [{"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).", "score": null, "metadata": {"source": "markdown_output/Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "year": "2010", "ingest_kind": "existing_chroma", "title": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR", "journal": "Applied Physics A", "doi": "10.1007/s00339-010-5673-5", "source_file": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "chunk_index": 4}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "score": null, "metadata": {"year": "2010", "doi": "10.1007/s00339-010-5673-5", "title": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR", "journal": "Applied Physics A", "source_file": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "chunk_index": 6}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "score": null, "snippets": [{"text": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "score": null, "metadata": {"chunk_index": "49", "year": "2017", "source_file": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "15", "ingest_kind": "pdf_fulltext", "doi": "10.1186/s40494-017-0125-6", "source": "On the stability of mediaeval inorganic pigments - a review"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Alteration of azurite into paratacamite at the St.", "score": null, "snippets": [{"text": "Alteration of azurite into paratacamite at the St.", "score": null, "metadata": {"source": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "chunk_index": "91", "doi": "10.1186/s40494-017-0125-6", "year": "2017", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "22", "source_file": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Alteration of azurite into paratacamite at the St.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 4, "resolver_scanned": 2314, "resolver_candidates": 157, "resolver_kept": 6, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 7, "lexical_scanned": 2314, "lexical_candidates": 299, "lexical_kept": 12, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/47bafa4d6475ff966ed43ad8908c2a82486933a8.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[Biogenic]--> β-PbO2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nThe transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59]. Besides, the use of plattnerite as a black pigment has also been proposed to explain paint micro-sample analyses [60]. ### Factors influencing red lead alteration Humidity is supposed to play a role through the activation of chemical processes [29], as well as its ability to support microbial development, which may generate alteration of lead-containing pigments [65].\n\n[1] Evidence classification: edge 1: direct\nThe darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].\n\n[1] Evidence classification: edge 1: direct\nIf red lead darkening on frescoes is usually attributed to the formation of plattnerite, most of the studies related to red lead alteration on manuscripts point out its transformation into lead sulfide (galena, PbS). Such a phenomenon may occur through the interaction with atmospheric hydrogen sulfide [70]. Alternatively, in the case of tempera-like paintings, lead-based pigments alteration into lead sulfide may originate from metabolic activity of certain bacterial species, which generates hydrogen sulfide [71].\n\n[2] Evidence classification: edge 1: direct\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\n\n[2] Evidence classification: edge 1: direct\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "ref_list": ["AZE S, VALLET JM, DETALLE V, et al. Chromatic alterations of red lead pigments in artworks: a review [J/OL]. Phase Transitions, 2008. DOI: 10.1080/01411590701514326.", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001.", "ROSADO T, GIL M, MIRÃO J, et al. Darkening on lead‐based pigments: Microbiological contribution [J/OL]. Color Research & Application, 2016. DOI: 10.1002/col.22014."], "ref_snippets": [{"text": "The transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59]. Besides, the use of plattnerite as a black pigment has also been proposed to explain paint micro-sample analyses [60]. ### Factors influencing red lead alteration Humidity is supposed to play a role through the activation of chemical processes [29], as well as its ability to support microbial development, which may generate alteration of lead-containing pigments [65].\nThe darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].\nIf red lead darkening on frescoes is usually attributed to the formation of plattnerite, most of the studies related to red lead alteration on manuscripts point out its transformation into lead sulfide (galena, PbS). Such a phenomenon may occur through the interaction with atmospheric hydrogen sulfide [70]. Alternatively, in the case of tempera-like paintings, lead-based pigments alteration into lead sulfide may originate from metabolic activity of certain bacterial species, which generates hydrogen sulfide [71].", "score": null, "snippets": [{"text": "The transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59]. Besides, the use of plattnerite as a black pigment has also been proposed to explain paint micro-sample analyses [60]. ### Factors influencing red lead alteration Humidity is supposed to play a role through the activation of chemical processes [29], as well as its ability to support microbial development, which may generate alteration of lead-containing pigments [65].", "score": null, "metadata": {"chunk_index": 15, "title": "Chromatic alterations of red lead pigments in artworks: a review", "journal": "Phase Transitions", "ingest_kind": "existing_chroma", "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md", "source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "year": "2008", "doi": "10.1080/01411590701514326"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Biogenic", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59]. Besides, the use of plattnerite as a black pigment has also been proposed to explain paint micro-sample analyses [60]. ### Factors influencing red lead alteration Humidity is supposed to play a role through the activation of chemical processes [29], as well as its ability to support microbial development, which may generate alteration of lead-containing pigments [65].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "red lead", "product_span": "beta-PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].", "score": null, "metadata": {"doi": "10.1080/01411590701514326", "journal": "Phase Transitions", "year": "2008", "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md", "title": "Chromatic alterations of red lead pigments in artworks: a review", "source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "chunk_index": 16, "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Biogenic", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "If red lead darkening on frescoes is usually attributed to the formation of plattnerite, most of the studies related to red lead alteration on manuscripts point out its transformation into lead sulfide (galena, PbS). Such a phenomenon may occur through the interaction with atmospheric hydrogen sulfide [70]. Alternatively, in the case of tempera-like paintings, lead-based pigments alteration into lead sulfide may originate from metabolic activity of certain bacterial species, which generates hydrogen sulfide [71].", "score": null, "metadata": {"source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "chunk_index": 19, "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md", "title": "Chromatic alterations of red lead pigments in artworks: a review", "year": "2008", "ingest_kind": "existing_chroma", "journal": "Phase Transitions", "doi": "10.1080/01411590701514326"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Biogenic", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "If red lead darkening on frescoes is usually attributed to the formation of plattnerite, most of the studies related to red lead alteration on manuscripts point out its transformation into lead sulfide (galena, PbS). Such a phenomenon may occur through the interaction with atmospheric hydrogen sulfide [70]. Alternatively, in the case of tempera-like paintings, lead-based pigments alteration into lead sulfide may originate from metabolic activity of certain bacterial species, which generates hydrogen sulfide [71].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "score": null, "snippets": [{"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "score": null, "metadata": {"title": "Degradation of lead-based pigments by salt solutions", "year": "2009", "doi": "10.1016/j.culher.2008.11.001", "source_file": "Degradation of lead-based pigments by salt solutions.md", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "chunk_index": 42, "journal": "Journal of Cultural Heritage", "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Biogenic", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "score": null, "metadata": {"ingest_kind": "existing_chroma", "journal": "Journal of Cultural Heritage", "source_file": "Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "year": "2009", "doi": "10.1016/j.culher.2008.11.001", "chunk_index": 45}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Biogenic", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 64, "resolver_kept": 5, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 205, "lexical_kept": 5, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/4982a1806486aacac6f59aa62dbea49cdeb54a7f.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[12000lux+1.5W/m2+60℃+90%RH]--> CuCO3·Cu(OH)2 --[Chloride]--> Cu2Cl(OH)3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nBesides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.\n\n[2] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].\n\n[3] Evidence classification: edge 2: direct, pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nMinerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nCavallo, Alteration of azurite into paratacamite at the St.\n\n[4] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nSeveral authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.\n\n[6] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\n\n[6] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).\n\n[7] Evidence classification: edge 2: direct, pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nThe alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).\n\n[8] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nHowever, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].\n\n[9] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlteration of azurite into paratacamite at the St.", "ref_list": ["VAGNINI M, VIVANI R, VISCUSO E, et al. Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi [J/OL]. Vibrational Spectroscopy, 2018. DOI: 10.1016/j.vibspec.2018.07.006.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1.", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001.", "LLUVERAS A, BOULARAND S, ANDREOTTI A, et al. Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR [J/OL]. Applied Physics A, 2010. DOI: 10.1007/s00339-010-5673-5.", "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:15. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:22. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)"], "ref_snippets": [{"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": 0.4179467558860779, "snippets": [{"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": 0.4179467558860779, "metadata": {"source": "markdown_output/Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "title": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi", "year": "2018", "journal": "Vibrational Spectroscopy", "doi": "10.1016/j.vibspec.2018.07.006", "source_file": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "chunk_index": 38, "ingest_kind": "existing_chroma"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": 0.4175853729248047, "snippets": [{"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": 0.4175853729248047, "metadata": {"title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "journal": "Heritage Science", "source": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext", "doi": "10.1186/s40494-017-0125-6", "page": "13", "source_file": "On the stability of mediaeval inorganic pigments - a review", "year": "2017", "chunk_index": "38"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\nCavallo, Alteration of azurite into paratacamite at the St.", "score": null, "snippets": [{"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "metadata": {"ingest_kind": "pdf_fulltext", "year": "2024", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "license": "https://creativecommons.org/licenses/by/4.0", "source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "chunk_index": 22, "doi": "10.1007/s00339-024-07954-1", "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "journal": "Applied Physics A", "page": 11, "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Cavallo, Alteration of azurite into paratacamite at the St.", "score": null, "metadata": {"ingest_kind": "pdf_fulltext", "doi": "10.1007/s00339-024-07954-1", "source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "chunk_index": 43, "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "year": "2024", "page": 19, "license": "https://creativecommons.org/licenses/by/4.0", "journal": "Applied Physics A", "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Cavallo, Alteration of azurite into paratacamite at the St.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": null, "snippets": [{"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": null, "metadata": {"ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "journal": "Journal of Cultural Heritage", "year": "2009", "source_file": "Degradation of lead-based pigments by salt solutions.md", "doi": "10.1016/j.culher.2008.11.001", "chunk_index": 0}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "score": null, "snippets": [{"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).", "score": null, "metadata": {"source": "markdown_output/Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "year": "2010", "ingest_kind": "existing_chroma", "title": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR", "journal": "Applied Physics A", "doi": "10.1007/s00339-010-5673-5", "source_file": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "chunk_index": 4}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "score": null, "metadata": {"year": "2010", "doi": "10.1007/s00339-010-5673-5", "title": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR", "journal": "Applied Physics A", "source_file": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "chunk_index": 6}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "score": null, "snippets": [{"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "score": null, "metadata": {"title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "doi": "10.3390/min10050424", "ingest_kind": "pdf_direct", "journal": "Minerals", "year": "2020", "chunk_index": 5, "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "source": "pdf_direct/min10050424_part2.pdf"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "score": null, "metadata": {"ingest_kind": "pdf_direct", "source": "pdf_direct/min10050424_part2.pdf", "chunk_index": 7, "doi": "10.3390/min10050424", "year": "2020", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "journal": "Minerals", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": null, "snippets": [{"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": null, "metadata": {"ingest_kind": "pdf_reextract", "year": "2008", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "chunk_index": 0, "journal": "Journal of Raman Spectroscopy", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "doi": "10.1002/jrs.1845", "title": "Raman spectroscopic analysis of azurite blackening"}, "evidence_level": "edge_direct", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "clinoatacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "clinoatacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "score": null, "snippets": [{"text": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "score": null, "metadata": {"chunk_index": "49", "year": "2017", "source_file": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "15", "ingest_kind": "pdf_fulltext", "doi": "10.1186/s40494-017-0125-6", "source": "On the stability of mediaeval inorganic pigments - a review"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Alteration of azurite into paratacamite at the St.", "score": null, "snippets": [{"text": "Alteration of azurite into paratacamite at the St.", "score": null, "metadata": {"source": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "chunk_index": "91", "doi": "10.1186/s40494-017-0125-6", "year": "2017", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "22", "source_file": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Alteration of azurite into paratacamite at the St.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 2, "resolver_scanned": 2314, "resolver_candidates": 157, "resolver_kept": 6, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 5, "lexical_scanned": 2314, "lexical_candidates": 294, "lexical_kept": 12, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/4a39a4bba9a5f29819f6abee0e69e26dd291eac0.json

@@ -0,0 +1 @@
+{"root_material": "As2S3", "path_str": "As2S3 --[Binder]--> As(III)aq --[Binder]--> As(V)aq --[Binder]--> M3​(AsO4​)n​", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 3: direct\nAs it is improbable to encounter such very low or very high levels of humidity in a painting’s environment, this was not within the scope of our research. As(V) species can form metal arsenates with different cations, among which Pb 2+ , Fe 2+ , and Ca 2+ . All of these cations are very commonly encountered in historical oil paintings.\n\n[1] Evidence classification: edge 1: direct, edge 2: direct\nAdditionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.\n\n[1] Evidence classification: edge 2: direct\nThe relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "ref_list": ["BROERS FTH, JANSSENS K, WEKER JN, et al. Two Pathways for the Degradation of Orpiment Pigment (As2S3) Found in Paintings [J/OL]. Journal of the American Chemical Society, 2023. DOI: 10.1021/jacs.2c12271."], "ref_snippets": [{"text": "As it is improbable to encounter such very low or very high levels of humidity in a painting’s environment, this was not within the scope of our research. As(V) species can form metal arsenates with different cations, among which Pb 2+ , Fe 2+ , and Ca 2+ . All of these cations are very commonly encountered in historical oil paintings.\nAdditionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.\nThe relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "score": 0.5129972696304321, "snippets": [{"text": "As it is improbable to encounter such very low or very high levels of humidity in a painting’s environment, this was not within the scope of our research. As(V) species can form metal arsenates with different cations, among which Pb 2+ , Fe 2+ , and Ca 2+ . All of these cations are very commonly encountered in historical oil paintings.", "score": 0.5129972696304321, "metadata": {"ingest_kind": "pdf_fulltext", "chunk_index": 28, "license": "https://creativecommons.org/licenses/by/4.0/", "journal": "Journal of the American Chemical Society", "fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "year": "2023", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "doi": "10.1021/jacs.2c12271", "page": 11, "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "authors": [{"family": "Broers", "given": "Fréderique T. H."}, {"family": "Janssens", "given": "Koen"}, {"family": "Nelson Weker", "given": "Johanna"}, {"family": "Webb", "given": "Samuel M."}, {"family": "Mehta", "given": "Apurva"}, {"family": "Meirer", "given": "Florian"}, {"family": "Keune", "given": "Katrien"}], "volume": "145", "issue": "16", "pages": "8847-8859", "url": "https://doi.org/10.1021/jacs.2c12271"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 3, "reactant": "As(V)aq", "product": "M3(AsO4)n", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "As it is improbable to encounter such very low or very high levels of humidity in a painting’s environment, this was not within the scope of our research. As(V) species can form metal arsenates with different cations, among which Pb 2+ , Fe 2+ , and Ca 2+ . All of these cations are very commonly encountered in historical oil paintings.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "as(v)", "product_span": "metal arsenates", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "score": 0.5166073441505432, "metadata": {"license": "https://creativecommons.org/licenses/by/4.0/", "doi": "10.1021/jacs.2c12271", "ingest_kind": "pdf_fulltext", "year": "2023", "journal": "Journal of the American Chemical Society", "chunk_index": 20, "fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "page": 9, "authors": [{"family": "Broers", "given": "Fréderique T. H."}, {"family": "Janssens", "given": "Koen"}, {"family": "Nelson Weker", "given": "Johanna"}, {"family": "Webb", "given": "Samuel M."}, {"family": "Mehta", "given": "Apurva"}, {"family": "Meirer", "given": "Florian"}, {"family": "Keune", "given": "Katrien"}], "volume": "145", "issue": "16", "pages": "8847-8859", "url": "https://doi.org/10.1021/jacs.2c12271"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As2S3", "product": "As(III)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "orpiment", "product_span": "as(iii)", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 2, "reactant": "As(III)aq", "product": "As(V)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "as(iii)", "product_span": "as(v)", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "score": 0.525489330291748, "metadata": {"license": "https://creativecommons.org/licenses/by/4.0/", "chunk_index": 18, "ingest_kind": "pdf_fulltext", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "year": "2023", "doi": "10.1021/jacs.2c12271", "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "page": 8, "fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "journal": "Journal of the American Chemical Society", "authors": [{"family": "Broers", "given": "Fréderique T. H."}, {"family": "Janssens", "given": "Koen"}, {"family": "Nelson Weker", "given": "Johanna"}, {"family": "Webb", "given": "Samuel M."}, {"family": "Mehta", "given": "Apurva"}, {"family": "Meirer", "given": "Florian"}, {"family": "Keune", "given": "Katrien"}], "volume": "145", "issue": "16", "pages": "8847-8859", "url": "https://doi.org/10.1021/jacs.2c12271"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 2, "reactant": "As(III)aq", "product": "As(V)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "arsenite", "product_span": "arsenate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 25, "dense_candidates": 500, "dense_kept": 3, "resolver_scanned": 2314, "resolver_candidates": 0, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 3, "lexical_scanned": 2314, "lexical_candidates": 108, "lexical_kept": 3, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/4c096eb0ada014b5f468868a76c61cf3d0e34454.json

@@ -0,0 +1 @@
+{"root_material": "As2S3", "path_str": "As2S3 --[Binder]--> As(III)aq --[Binder]--> As(V)aq", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct, edge 2: direct, pathway endpoints As2S3 -> As(V)aq: direct\nAdditionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.\n\n[1] Evidence classification: edge 2: direct\nThe relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.\n\n[2] Evidence classification: pathway endpoints As2S3 -> As(V)aq: direct\nArsenates (As 5+) are formed from orpiment, realgar and emerald green degradation: these ions are water soluble and migrate throughout the whole painting, accumulat - ing at interfaces between layers, around Fe/Mn rich par - ticles, and according to the local pH conditions in the paint layer. Due to this water-based transport, appro - priate cleaning solvents must be selected, and relative humidity controlled [180, 183]. It seems that polysaccha - ridic media, or egg yolk, negatively affect the stability of the arsenic sulphide pigments [184].", "ref_list": ["BROERS FTH, JANSSENS K, WEKER JN, et al. Two Pathways for the Degradation of Orpiment Pigment (As2S3) Found in Paintings [J/OL]. Journal of the American Chemical Society, 2023. DOI: 10.1021/jacs.2c12271.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:15. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)"], "ref_snippets": [{"text": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.\nThe relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "score": 0.516607403755188, "snippets": [{"text": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "score": 0.516607403755188, "metadata": {"fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "journal": "Journal of the American Chemical Society", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "ingest_kind": "pdf_fulltext", "doi": "10.1021/jacs.2c12271", "year": "2023", "page": 9, "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "chunk_index": 20, "license": "https://creativecommons.org/licenses/by/4.0/", "authors": [{"family": "Broers", "given": "Fréderique T. H."}, {"family": "Janssens", "given": "Koen"}, {"family": "Nelson Weker", "given": "Johanna"}, {"family": "Webb", "given": "Samuel M."}, {"family": "Mehta", "given": "Apurva"}, {"family": "Meirer", "given": "Florian"}, {"family": "Keune", "given": "Katrien"}], "volume": "145", "issue": "16", "pages": "8847-8859", "url": "https://doi.org/10.1021/jacs.2c12271"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As2S3", "product": "As(III)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "orpiment", "product_span": "as(iii)", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 2, "reactant": "As(III)aq", "product": "As(V)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "as(iii)", "product_span": "as(v)", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "As2S3", "product": "As(V)aq", "condition": "Binder", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "orpiment", "product_span": "as(v)", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "score": null, "metadata": {"doi": "10.1021/jacs.2c12271", "journal": "Journal of the American Chemical Society", "page": 7, "chunk_index": 17, "ingest_kind": "pdf_fulltext", "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "license": "https://creativecommons.org/licenses/by/4.0/", "fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "year": "2023", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "authors": [{"family": "Broers", "given": "Fréderique T. H."}, {"family": "Janssens", "given": "Koen"}, {"family": "Nelson Weker", "given": "Johanna"}, {"family": "Webb", "given": "Samuel M."}, {"family": "Mehta", "given": "Apurva"}, {"family": "Meirer", "given": "Florian"}, {"family": "Keune", "given": "Katrien"}], "volume": "145", "issue": "16", "pages": "8847-8859", "url": "https://doi.org/10.1021/jacs.2c12271"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "As(III)aq", "product": "As(V)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The relatively high concentration of As in the medium and the XANES of positions 2−4 suggest that some of the arsenolite had dissolved in the water-diluted egg yolk (since orpiment is less soluble in water than arsenolite, this phenomenon was not observed in the previous experiment 41,42 ). Literature shows that during solution of arsenolite, first hydrated arsenite species form, after which oxidation to arsenate species takes place.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "arsenite", "product_span": "arsenate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Arsenates (As 5+) are formed from orpiment, realgar and emerald green degradation: these ions are water soluble and migrate throughout the whole painting, accumulat - ing at interfaces between layers, around Fe/Mn rich par - ticles, and according to the local pH conditions in the paint layer. Due to this water-based transport, appro - priate cleaning solvents must be selected, and relative humidity controlled [180, 183]. It seems that polysaccha - ridic media, or egg yolk, negatively affect the stability of the arsenic sulphide pigments [184].", "score": null, "snippets": [{"text": "Arsenates (As 5+) are formed from orpiment, realgar and emerald green degradation: these ions are water soluble and migrate throughout the whole painting, accumulat - ing at interfaces between layers, around Fe/Mn rich par - ticles, and according to the local pH conditions in the paint layer. Due to this water-based transport, appro - priate cleaning solvents must be selected, and relative humidity controlled [180, 183]. It seems that polysaccha - ridic media, or egg yolk, negatively affect the stability of the arsenic sulphide pigments [184].", "score": null, "metadata": {"doi": "10.1186/s40494-017-0125-6", "journal": "Heritage Science", "source": "On the stability of mediaeval inorganic pigments - a review", "year": "2017", "page": "15", "ingest_kind": "pdf_fulltext", "source_file": "On the stability of mediaeval inorganic pigments - a review", "chunk_index": "51", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "As2S3", "product": "As(V)aq", "condition": "Binder", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Arsenates (As 5+) are formed from orpiment, realgar and emerald green degradation: these ions are water soluble and migrate throughout the whole painting, accumulat - ing at interfaces between layers, around Fe/Mn rich par - ticles, and according to the local pH conditions in the paint layer. Due to this water-based transport, appro - priate cleaning solvents must be selected, and relative humidity controlled [180, 183]. It seems that polysaccha - ridic media, or egg yolk, negatively affect the stability of the arsenic sulphide pigments [184].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "orpiment", "product_span": "arsenates", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 17, "dense_candidates": 340, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 0, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 2, "lexical_scanned": 2314, "lexical_candidates": 108, "lexical_kept": 3, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/528d3b8d4a0cf97598cf2af6aacb5dc7310988b1.json

@@ -0,0 +1 @@
+{"root_material": "As4S4", "path_str": "As4S4 --[Uv+Oxidant]--> p-As4S4", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nThis means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).\n\n[1] Evidence classification: edge 1: direct\nIt summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy. The process of transformation takes place in four steps. The initiating photoreaction step requires oxygen and thereby the intermediate azonite (As4S5) and arsenolite (As2O3) are obtained (step 1).\n\n[1] Evidence classification: edge 1: direct\n(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.\n\n[1] Evidence classification: edge 1: direct\nFigure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).\n\n[1] Evidence classification: edge 1: direct\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in\n\n[1] Evidence classification: edge 1: direct\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "ref_list": ["JOVANOVSKI G, MAKRESKI P. Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization [J/OL]. ChemTexts, 2020. DOI: 10.1007/s40828-019-0100-9."], "ref_snippets": [{"text": "This means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).\nIt summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy. The process of transformation takes place in four steps. The initiating photoreaction step requires oxygen and thereby the intermediate azonite (As4S5) and arsenolite (As2O3) are obtained (step 1).\n(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.\nFigure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "score": 0.44365543127059937, "snippets": [{"text": "This means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).", "score": 0.4943835735321045, "metadata": {"doi": "10.1007/s40828-019-0100-9", "journal": "ChemTexts", "ingest_kind": "existing_chroma", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "chunk_index": 61, "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "This means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "It summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy. The process of transformation takes place in four steps. The initiating photoreaction step requires oxygen and thereby the intermediate azonite (As4S5) and arsenolite (As2O3) are obtained (step 1).", "score": 0.44497865438461304, "metadata": {"source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "ingest_kind": "existing_chroma", "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "chunk_index": 1, "doi": "10.1007/s40828-019-0100-9", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "It summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy. The process of transformation takes place in four steps. The initiating photoreaction step requires oxygen and thereby the intermediate azonite (As4S5) and arsenolite (As2O3) are obtained (step 1).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.", "score": 0.44365543127059937, "metadata": {"year": "2020", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "doi": "10.1007/s40828-019-0100-9", "chunk_index": 2, "ingest_kind": "existing_chroma", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Figure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).", "score": null, "metadata": {"journal": "ChemTexts", "ingest_kind": "existing_chroma", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "doi": "10.1007/s40828-019-0100-9", "year": "2020", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "chunk_index": 67, "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Figure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in", "score": null, "metadata": {"chunk_index": 73, "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "ingest_kind": "existing_chroma", "doi": "10.1007/s40828-019-0100-9", "journal": "ChemTexts", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "year": "2020", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "score": null, "metadata": {"source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "doi": "10.1007/s40828-019-0100-9", "chunk_index": 75, "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "ingest_kind": "existing_chroma", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 3, "resolver_scanned": 2314, "resolver_candidates": 157, "resolver_kept": 6, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 157, "lexical_kept": 6, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/5354f72e503de256e243b44194400d6b41f9645e.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv+Moisture]--> HgSO4 --[Uv+Moisture]--> Hg", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.\n\n[1] Evidence classification: edge 1: direct\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "ref_list": ["ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "ELERT K, CARDELL C. Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging [J/OL]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019, 216:236-248. DOI: 10.1016/j.saa.2019.03.027."], "ref_snippets": [{"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.\nwould explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": 0.40421152114868164, "snippets": [{"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.", "score": 0.49485206604003906, "metadata": {"source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "ingest_kind": "existing_chroma", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "chunk_index": 43, "year": "2021", "journal": "Communications Chemistry", "doi": "10.1038/s42004-021-00610-2"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52]. \\begin{split} 2\\mathrm{HgSO4(aq)+2e^{-}\\leftrightarrow Hg2^{2+}+ 2SO4^{2-}\\ is\\ 0.83\\ V\\ vs.\\ SHE}\\\\ (standard\\ hydrogen\\ electrode)\\end{split} \\tag{2} \\mathrm{Hg2^{2+}+2e^{-}\\leftrightarrow 2Hg\\ is\\ 0.80\\ V\\ vs.\\ SHE} \\tag{3} This implies that mercury sulfate could be reduced to metallic mercury in sequential reactions via photo-induced electron transfer. Indeed, part of the cinnabar pigment grains suffered darkening upon UV exposure, and a few nano-sized droplets, presumably metallic mercury, were observed on the pigment surface. However, massive amounts of yellow schuetteite (with a 3/1 Hg/S ratio), which covered large parts of the UV-aged pigment grains acted as a sink for mercury ions and limited the formation of metallic mercury.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "mercury sulfate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "score": 0.40421152114868164, "metadata": {"doi": "10.1038/s42004-021-00610-2", "title": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints", "year": "2021", "journal": "Communications Chemistry", "source_file": "Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md", "ingest_kind": "existing_chroma", "chunk_index": 42, "source": "markdown_output/Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints.md"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Moisture", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "would explain the presence of schuetteite and mercury sulfate hydrate on UV-exposed cinnabar pigment grains in our study. They form according to the following overall reaction for the photoconversion process at high RH (adapted from Meissner et al.[49], h{}^{+}= hole): \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} \\mathrm{HgS+4h^{+}+2H2O+O2\\to Hg^{2+}+SO4^{2-}+4H^{+}} \\tag{1} Considering the potential of redox reactions for mercury sulfate and mercury ions (reactions 2 and 3), it becomes obvious that both fall within the band gap of cinnabar[52].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "cinnabar", "product_span": "mercury sulfate", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 2, "resolver_scanned": 2314, "resolver_candidates": 16, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 214, "lexical_kept": 2, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/5496d9a92a226f46e43a5e44a401bcde6b1e8f1d.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Chloride]--> CuCl --[Chloride]--> Cu2Cl(OH)3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].\n\n[2] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nBesides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nMinerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\n\n[4] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nSeveral authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).\n\n[6] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nThe alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "ref_list": ["On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "VAGNINI M, VIVANI R, VISCUSO E, et al. Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi [J/OL]. Vibrational Spectroscopy, 2018. DOI: 10.1016/j.vibspec.2018.07.006.", "PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1.", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001.", "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845."], "ref_snippets": [{"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": 0.4182766079902649, "snippets": [{"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": 0.4182766079902649, "metadata": {"title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "source_file": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext", "chunk_index": "38", "journal": "Heritage Science", "doi": "10.1186/s40494-017-0125-6", "year": "2017", "page": "13", "source": "On the stability of mediaeval inorganic pigments - a review"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": 0.42595595121383667, "snippets": [{"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": 0.42595595121383667, "metadata": {"ingest_kind": "existing_chroma", "title": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi", "doi": "10.1016/j.vibspec.2018.07.006", "year": "2018", "chunk_index": 38, "journal": "Vibrational Spectroscopy", "source": "markdown_output/Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "source_file": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "snippets": [{"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "metadata": {"source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "page": 11, "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "year": "2024", "chunk_index": 22, "license": "https://creativecommons.org/licenses/by/4.0", "doi": "10.1007/s00339-024-07954-1", "journal": "Applied Physics A", "ingest_kind": "pdf_fulltext", "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": null, "snippets": [{"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": null, "metadata": {"ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "journal": "Journal of Cultural Heritage", "year": "2009", "source_file": "Degradation of lead-based pigments by salt solutions.md", "doi": "10.1016/j.culher.2008.11.001", "chunk_index": 0}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "score": null, "snippets": [{"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "score": null, "metadata": {"title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "doi": "10.3390/min10050424", "ingest_kind": "pdf_direct", "journal": "Minerals", "year": "2020", "chunk_index": 5, "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "source": "pdf_direct/min10050424_part2.pdf"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "score": null, "metadata": {"ingest_kind": "pdf_direct", "source": "pdf_direct/min10050424_part2.pdf", "chunk_index": 7, "doi": "10.3390/min10050424", "year": "2020", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "journal": "Minerals", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": null, "snippets": [{"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": null, "metadata": {"ingest_kind": "pdf_reextract", "year": "2008", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "chunk_index": 0, "journal": "Journal of Raman Spectroscopy", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "doi": "10.1002/jrs.1845", "title": "Raman spectroscopic analysis of azurite blackening"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "clinoatacamite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 2, "resolver_scanned": 2314, "resolver_candidates": 8, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 5, "lexical_scanned": 2314, "lexical_candidates": 229, "lexical_kept": 7, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/5bda912817ed611583b31a7acef51a21b1ff588d.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Alkaline]--> Cu(OH)2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\ndesantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.\n\n[2] Evidence classification: edge 1: direct\nThe treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "ref_list": ["MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845.", "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424."], "ref_snippets": [{"text": "desantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.", "score": 0.4565846920013428, "snippets": [{"text": "desantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.", "score": 0.4565846920013428, "metadata": {"title": "Raman spectroscopic analysis of azurite blackening", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "year": "2008", "chunk_index": 2, "ingest_kind": "pdf_reextract", "journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.1845", "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu(OH)2", "condition": "Alkaline", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "desantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "copper hydroxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "score": null, "snippets": [{"text": "The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "score": null, "metadata": {"source": "pdf_direct/min10050424_part2.pdf", "chunk_index": 6, "year": "2020", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "ingest_kind": "pdf_direct", "doi": "10.3390/min10050424", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "journal": "Minerals"}, "evidence_level": "edge_direct", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu(OH)2", "condition": "Alkaline", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "copper hydroxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 30, "resolver_kept": 2, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 2, "lexical_scanned": 2314, "lexical_candidates": 226, "lexical_kept": 2, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/60ea96ed1016b93caf4e95daafb286edd228200c.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[12000lux+1.5W/m2+60℃+90%RH]--> CuCO3·Cu(OH)2 --[Biogenic+Chloride]--> Cu2Cl(OH)3", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nBesides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.\n\n[2] Evidence classification: edge 2: direct, pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nMinerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\n\n[2] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nCavallo, Alteration of azurite into paratacamite at the St.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nSeveral authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.\n\n[4] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).\n\n[4] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\n\n[5] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).\n\n[6] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nThe alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).\n\n[7] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAzurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].\n\n[8] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nHowever, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].\n\n[9] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> Cu2Cl(OH)3: direct\nAlteration of azurite into paratacamite at the St.", "ref_list": ["VAGNINI M, VIVANI R, VISCUSO E, et al. Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi [J/OL]. Vibrational Spectroscopy, 2018. DOI: 10.1016/j.vibspec.2018.07.006.", "PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1.", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001.", "LLUVERAS A, BOULARAND S, ANDREOTTI A, et al. Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR [J/OL]. Applied Physics A, 2010. DOI: 10.1007/s00339-010-5673-5.", "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424.", "MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845.", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:15. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:22. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)"], "ref_snippets": [{"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": 0.4179467558860779, "snippets": [{"text": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "score": 0.4179467558860779, "metadata": {"journal": "Vibrational Spectroscopy", "source_file": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "title": "Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi", "chunk_index": 38, "doi": "10.1016/j.vibspec.2018.07.006", "source": "markdown_output/Investigation on the process of lead white blackening by Raman spectroscopy, XRD and other methods: Study of Cimabue’s paintings in Assisi.md", "ingest_kind": "existing_chroma", "year": "2018"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Besides, it emerges clearly that the painting has been heavily contaminated by one or more chlorine compounds; in fact, not only the degradation of azurite to basic copper chlorides (namely, the two polymorph forms atacamite and clinonatacamite), but also the partial alteration of hematite to iron oxide chloride has been found. All these findings suggest an interesting hypothesis that deserves to be deepened: a chlorine compound could have played a role in the degradation of the Cimabue's paintings examined in this work as it has been recently observed for cinnabar [2, 40] and for the alteration of azurite [41, 42] in panel paintings.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.\nCavallo, Alteration of azurite into paratacamite at the St.", "score": null, "snippets": [{"text": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "score": null, "metadata": {"page": 11, "source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "year": "2024", "chunk_index": 22, "journal": "Applied Physics A", "doi": "10.1007/s00339-024-07954-1", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "ingest_kind": "pdf_fulltext", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "license": "https://creativecommons.org/licenses/by/4.0", "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 2, "reactant": "CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "Biogenic+Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "malachite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Minerals from the atacamite family are common alteration or degradation products of azurite and malachite, especially in wall paintings and murals [64, 65]. Medieval synthetic recipes producing purely atacamite have also been documented [18] The specific identity of the basic copper chloride is therefore of interest, since it could provide information about the origin and mechanism of formation in the sample. Further analysis by /u1D707XANES was therefore carried out on sample T1 to characterise its composition.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Cavallo, Alteration of azurite into paratacamite at the St.", "score": null, "metadata": {"license": "https://creativecommons.org/licenses/by/4.0", "source": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "fulltext_url": "https://cnrs.hal.science/hal-05105620/document", "page": 19, "year": "2024", "doi": "10.1007/s00339-024-07954-1", "journal": "Applied Physics A", "chunk_index": 43, "source_file": "Characterisation_of_rouaite_an_unusual_copper-containing_pigment_in_early_modern_English_w_92a10740da0a.pdf", "title": "Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy", "ingest_kind": "pdf_fulltext", "authors": [{"family": "Purdy", "given": "Ellen H."}, {"family": "Critchley", "given": "Sarah"}, {"family": "Holé", "given": "Clément"}, {"family": "Cotte", "given": "Marine"}, {"family": "Kirkham", "given": "Andrea"}, {"family": "Casford", "given": "Michael"}], "volume": "130", "issue": "11", "article_number": "817", "url": "https://doi.org/10.1007/s00339-024-07954-1"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Cavallo, Alteration of azurite into paratacamite at the St.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": null, "snippets": [{"text": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "score": null, "metadata": {"ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "title": "Degradation of lead-based pigments by salt solutions", "journal": "Journal of Cultural Heritage", "year": "2009", "source_file": "Degradation of lead-based pigments by salt solutions.md", "doi": "10.1016/j.culher.2008.11.001", "chunk_index": 0}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Several authors [5, 6, 7] have reported on the alteration of the blue pigment azurite to green atacamite due to its reaction with NaCl solution; such a colour change profoundly distorts the character and artistic impression of the art work.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "atacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).\nAzurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "score": null, "snippets": [{"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).", "score": null, "metadata": {"source": "markdown_output/Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "year": "2010", "ingest_kind": "existing_chroma", "title": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR", "journal": "Applied Physics A", "doi": "10.1007/s00339-010-5673-5", "source_file": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "chunk_index": 4}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "score": null, "metadata": {"year": "2010", "doi": "10.1007/s00339-010-5673-5", "title": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR", "journal": "Applied Physics A", "source_file": "Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR.md", "chunk_index": 6}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite, although being stable to light and atmosphere, presents frequent chromatic alterations to greenish tonalities due to transformation into paratacamite and atacamite (Cu2Cl(OH)3) [2, 3, 8, 9] and also malachite (CuCO3\\cdotCu(OH)2) [1], not yet completely understood. Samples analyzed come from a gypsum shield on top of a door in the Monastery of Santos Creus (Catalonia, Spain) dating from the 1605 AD. The shield is depicted mainly in blue and brown in order to underline the relieves with the monastery insignias. In the blue areas, green shades could easily be identified (Fig. 1a). Synchrotron radiation X-ray diffraction and synchrotron IR microscopy have been used to produce maps of phases and high contrast chemical imaging.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].\nAlso, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "score": null, "snippets": [{"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "score": null, "metadata": {"title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints", "doi": "10.3390/min10050424", "ingest_kind": "pdf_direct", "journal": "Minerals", "year": "2020", "chunk_index": 5, "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "source": "pdf_direct/min10050424_part2.pdf"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "score": null, "metadata": {"ingest_kind": "pdf_direct", "source": "pdf_direct/min10050424_part2.pdf", "chunk_index": 7, "doi": "10.3390/min10050424", "year": "2020", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "journal": "Minerals", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Also, the exposure of historical azurite tempera paints to chloride-rich water (like those of rivers or sea floods) can lead to precipitation of green paratacamite ((Cu 2+)3(Cu,Zn)(OH)6Cl2) [33]. The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": null, "snippets": [{"text": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "score": null, "metadata": {"ingest_kind": "pdf_reextract", "year": "2008", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "chunk_index": 0, "journal": "Journal of Raman Spectroscopy", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "doi": "10.1002/jrs.1845", "title": "Raman spectroscopic analysis of azurite blackening"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The alteration most frequently studied is the discoloration from blue to green due to the degradation of azurite into malachite 3 (a similar basic copper carbonate, (CuCO 3ÐCu(OH)2)o ri n t o any basic copper chloride 4 (into one of the three isomers atacamite, paratacamite or clinoatacamite).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "clinoatacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": null, "snippets": [{"text": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "score": null, "metadata": {"journal": "Heritage Science", "year": "2017", "page": "13", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "ingest_kind": "pdf_fulltext", "source_file": "On the stability of mediaeval inorganic pigments - a review", "chunk_index": "38", "doi": "10.1186/s40494-017-0125-6", "source": "On the stability of mediaeval inorganic pigments - a review"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "score": null, "snippets": [{"text": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "score": null, "metadata": {"chunk_index": "49", "year": "2017", "source_file": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "15", "ingest_kind": "pdf_fulltext", "doi": "10.1186/s40494-017-0125-6", "source": "On the stability of mediaeval inorganic pigments - a review"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "However, an interesting example is reported in literature: after the 1966 flood in Florence, green paratacamite was formed on azurite-containing wall paintings [115].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Alteration of azurite into paratacamite at the St.", "score": null, "snippets": [{"text": "Alteration of azurite into paratacamite at the St.", "score": null, "metadata": {"source": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "chunk_index": "91", "doi": "10.1186/s40494-017-0125-6", "year": "2017", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "page": "22", "source_file": "On the stability of mediaeval inorganic pigments - a review", "ingest_kind": "pdf_fulltext"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "lexical", "retrieval_routes": ["lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu2Cl(OH)3", "condition": "", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Alteration of azurite into paratacamite at the St.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "paratacamite", "relation_basis": "observed_conversion", "condition_status": "not_applicable", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 21, "dense_candidates": 420, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 157, "resolver_kept": 6, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 5, "lexical_scanned": 2314, "lexical_candidates": 297, "lexical_kept": 12, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/62fefad4da30a7af1247f653f0139aff940e74a5.json

@@ -0,0 +1 @@
+{"root_material": "As2S3", "path_str": "As2S3 --[Binder]--> As(III)aq", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nAdditionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "ref_list": ["BROERS FTH, JANSSENS K, WEKER JN, et al. Two Pathways for the Degradation of Orpiment Pigment (As2S3) Found in Paintings [J/OL]. Journal of the American Chemical Society, 2023. DOI: 10.1021/jacs.2c12271."], "ref_snippets": [{"text": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "score": 0.516607403755188, "snippets": [{"text": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "score": 0.516607403755188, "metadata": {"fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "journal": "Journal of the American Chemical Society", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "chunk_index": 20, "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "year": "2023", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "page": 9, "license": "https://creativecommons.org/licenses/by/4.0/", "doi": "10.1021/jacs.2c12271", "ingest_kind": "pdf_fulltext", "authors": [{"family": "Broers", "given": "Fréderique T. H."}, {"family": "Janssens", "given": "Koen"}, {"family": "Nelson Weker", "given": "Johanna"}, {"family": "Webb", "given": "Samuel M."}, {"family": "Mehta", "given": "Apurva"}, {"family": "Meirer", "given": "Florian"}, {"family": "Keune", "given": "Katrien"}], "volume": "145", "issue": "16", "pages": "8847-8859", "url": "https://doi.org/10.1021/jacs.2c12271"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As2S3", "product": "As(III)aq", "condition": "Binder", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Additionally, orpiment in Paraloid-72 (acrylic resin) was LA and a similar trend was observed as found in the sample with egg tempera, namely, the formation of As(III)−OH, followed by the formation and migration of As(V) species.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "orpiment", "product_span": "as(iii)", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 0, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 108, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/658d02f04826bbf5e188a9529548b74ff6c06e50.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Chloride]--> α-Hg3S2Cl2 --[Chloride]--> Hg2Cl2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct, edge 2: direct, pathway endpoints alpha-HgS -> Hg2Cl2: direct\nThe residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "ref_list": ["KEUNE K, BOON JJ. Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings [J/OL]. Analytical Chemistry, 2005. DOI: 10.1021/ac048158f.", "CHAPPÉ M, HILDENHAGEN J, DICKMANN K, et al. Laser irradiation of medieval pigments at IR, VIS and UV wavelengths [J/OL]. Journal of Cultural Heritage, 2003. DOI: 10.1016/s1296-2074(02)01206-2.", "COTTE M, SUSINI J, METRICH N, et al. Blackening of Pompeian Cinnabar Paintings: X-ray Microspectroscopy Analysis [J/OL]. Analytical Chemistry, 2006. DOI: 10.1021/ac0612224."], "ref_snippets": [{"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.5111522674560547, "snippets": [{"text": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "score": 0.5111522674560547, "metadata": {"year": "2005", "title": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings", "doi": "10.1021/ac048158f", "chunk_index": 46, "journal": "Analytical Chemistry", "ingest_kind": "existing_chroma", "source_file": "Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "source": "markdown_output/Analytical Imaging Studies Clarifying the Process of the Darkening of Vermilion in Paintings.md", "authors": [{"family": "Keune", "given": "Katrien"}, {"family": "Boon", "given": "Jaap J."}], "volume": "77", "issue": "15", "pages": "4742-4750", "url": "https://doi.org/10.1021/ac048158f"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "alpha-HgS", "product": "alpha-Hg3S2Cl2", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "corderoite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 2, "reactant": "alpha-Hg3S2Cl2", "product": "Hg2Cl2", "condition": "Chloride", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "corderoite", "product_span": "calomel", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}, {"edge_index": 0, "reactant": "alpha-HgS", "product": "Hg2Cl2", "condition": "Chloride", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The residual vermilion reacts with this external chloride to the light-sensitive mineral corderoite, which degrades under the influence of light into calomel, metallic mercury, and sulfur.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "vermilion", "product_span": "calomel", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [], "retrieval_trace": {"query_count": 20, "dense_candidates": 400, "dense_kept": 1, "resolver_scanned": 2314, "resolver_candidates": 16, "resolver_kept": 1, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 200, "lexical_kept": 1, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/6e07eeada6db2a42d40e0be0a4054d1fc453b59a.json

@@ -0,0 +1 @@
+{"root_material": "α-HgS", "path_str": "α-HgS --[Uv+Oxidant]--> HgSO4", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["CHAPPÉ M, HILDENHAGEN J, DICKMANN K, et al. Laser irradiation of medieval pigments at IR, VIS and UV wavelengths [J/OL]. Journal of Cultural Heritage, 2003. DOI: 10.1016/s1296-2074(02)01206-2.", "ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2."], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [{"source": "ELERT K, MENDOZA MP, CARDELL C. Direct evidence for metallic mercury causing photo-induced darkening of red cinnabar tempera paints [J/OL]. Communications Chemistry, 2021. DOI: 10.1038/s42004-021-00610-2.", "snippet": "the intensity and type of radiation having a rate-determining influence. Besides, schuettetic has been found in cinnabar deposits exposed to natural sunlight in numerous locations, including Almaden (Spain), California and Nevada (USA), Bolivia, Moravia (Czech Republic), and Sonora (Mexico) [48]. According to Bailey et al. [19], this mineral forms through photooxidation of sunlight-exposed cinnabar in the presence of oxygen-bearing surface water. Importantly, the authors acknowledged that HgSO\\({}_{4}\\) might be an intermediate phase during schuettetic formation. In any case, sulfate formation is not limited to cinnabar deposits. Radeport et al. [2, 17] acknowledged the possible oxidation of mercury sulfide to sulfate upon cinnabar degradation in the case of a Gothic wall painting from the monastery of Pedralbes (Barcelona, Spain) and detected mercury sulfate in artificially aged cinnabar pellets.", "retrieval_origin": "crn_provenance", "match": {"edge_index": 1, "reactant": "alpha-HgS", "product": "HgSO4", "condition": "Uv+Oxidant", "evidence_scope": "edge", "verdict": "inferred", "score": 0.87, "window": "According to Bailey et al. [19], this mineral forms through photooxidation of sunlight-exposed cinnabar in the presence of oxygen-bearing surface water. Importantly, the authors acknowledged that HgSO4 might be an intermediate phase during schuettetic formation. In any case, sulfate formation is not limited to cinnabar deposits. Radeport et al. [2, 17] acknowledged the possible oxidation of mercury sulfide to sulfate upon cinnabar degradation in the case of a Gothic wall painting from the monastery of Pedralbes (Barcelona, Spain) and detected mercury sulfate in artificially aged cinnabar pellets.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "mercury sulfide", "product_span": "mercury sulfate", "relation_basis": "author_proposal", "condition_status": "exact", "provenance_level": "unspecified", "reasons": ["relation_author_proposal"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 11, "dense_candidates": 220, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 15, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 203, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/71b36ce9625cb4b30bb36673b5661517e134f5a6.json

@@ -0,0 +1 @@
+{"root_material": "As4S4", "path_str": "As4S4 --[Uv]--> p-As4S4", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nThis means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).\n\n[1] Evidence classification: edge 1: direct\nIt summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy.\n\n[1] Evidence classification: edge 1: direct\n(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.\n\n[1] Evidence classification: edge 1: direct\nFigure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).\n\n[1] Evidence classification: edge 1: direct\n### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light ### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction\n\n[1] Evidence classification: edge 1: direct\nAlthough the complete mechanism of the photoinduced transformation of realgar to pararealgar on the atomic scale has been unraveled, the interest to continue exploring the light-induced transformation in the scientific community (by means of FTIR [75; 76], Raman spectroscopy [75; 76; 77], and X-ray diffraction [75; 77]) remains. In addition, recently the multistage reverse transformation of pararealgar to both As4S4 phases (beta-As4S4 and realgar) was revealed and described by X-ray powder diffraction (XRPD) [78] leading to better understanding of the photoinduced solid-solid transformation among these three As4S4 phases.\n\n[1] Evidence classification: edge 1: direct\n(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized. Polymorphs of minerals Phase transitions of polymorphs Realgar-pararealgar Photoinduced solid-state transition Single-crystal X-ray photodiffraction FTIR spectroscopy Raman spectroscopy Sulfur atom migration\n\n[1] Evidence classification: edge 1: direct\n### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction\n\n[1] Evidence classification: edge 1: direct\nAs it was already mentioned, once very small red crystals of realgar are exposed to direct visible light, they convert slowly to a yellow powder of pararealgar, and the process continues even after they have been stored in the dark [60].\n\n[1] Evidence classification: edge 1: direct\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in\n\n[1] Evidence classification: edge 1: direct\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).\n\n[2] Evidence classification: edge 1: direct\nThe Light-Induced Alteration of Realgar to Pararealgar.\n\n[3] Evidence classification: edge 1: direct\nSmall quantities of yellow crystalline pararealgar was obtained by natural light aging of natural realgar (Kremer Pigmente GmbH & Co, Aichstetten, Germany) while orange-red g-As40S60 was considered as reference for the amor- phous arsenic sul fide.\n\n[3] Evidence classification: edge 1: direct\nAs such, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58].\n\n[3] Evidence classification: edge 1: direct\nuch, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58]. Therefore, the migrated arsenic species identi fied in H1 (white line indicated by an arrow in Fig. 3) could not only be due to the degradation of the realgar crys- talline phase found in the glass pigment but can also find its origin in the degradation of the pararealgar remnants found in the amorphous material after its partial sublimation. Consequently, the presence of migrated arsenic degradation products and pararealgar does not ne- cessarily indicate a degradation of natural realgar used as primary source for the amorphous pigment. The analyzed particles in H1 are big enough (ca. 10 μm) to suppose that the center of the particle (where the Raman analyses were per- formed) has not yet been in fluenced by light.\n\n[4] Evidence classification: edge 1: direct\nRealgar on the other side, is known to degrade to pararealgar within days upon exposure to normal light levels [70].\n\n[4] Evidence classification: edge 1: direct\nBefore this date, the historical sources mention that light exposed realgar forms orpiment, which led to misinterpretation and up until almost 30 years ago, the friable yellow pararealgar generally was identified as orpiment [71, 72].\n\n[4] Evidence classification: edge 1: direct\nRadiation damage Pararealgar is known to be a light-induced degradation product of realgar as well as of the minerals in the alacranite (As8S9) series, both the natural and synthetic phases [2].\n\n[5] Evidence classification: edge 1: direct\nExposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].\n\n[6] Evidence classification: edge 1: direct\nThe light‐induced alteration of realgar to pararealgar.\n\n[7] Evidence classification: edge 1: direct\nThe light-induced alteration of realgar to pararealgar.", "ref_list": ["JOVANOVSKI G, MAKRESKI P. Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization [J/OL]. ChemTexts, 2020. DOI: 10.1007/s40828-019-0100-9.", "BROERS FTH, JANSSENS K, WEKER JN, et al. Two Pathways for the Degradation of Orpiment Pigment (As2S3) Found in Paintings [J/OL]. Journal of the American Chemical Society, 2023. DOI: 10.1021/jacs.2c12271.", "VERMEULEN M, SAVERWYNS S, COUDRAY A, et al. Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments [J/OL]. Dyes and Pigments, 2018. DOI: 10.1016/j.dyepig.2017.10.009.", "Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization [J/OL]. Heritage Science, 2024. DOI: 10.1186/s40494-024-01350-x. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:16. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:24. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "KEUNE K, MASS J, MEHTA A, et al. Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues [J/OL]. Heritage Science, 2016. DOI: 10.1186/s40494-016-0078-1."], "ref_snippets": [{"text": "This means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).\nIt summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy.\n(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.\nFigure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).\n### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light ### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction\nAlthough the complete mechanism of the photoinduced transformation of realgar to pararealgar on the atomic scale has been unraveled, the interest to continue exploring the light-induced transformation in the scientific community (by means of FTIR [75; 76], Raman spectroscopy [75; 76; 77], and X-ray diffraction [75; 77]) remains. In addition, recently the multistage reverse transformation of pararealgar to both As4S4 phases (beta-As4S4 and realgar) was revealed and described by X-ray powder diffraction (XRPD) [78] leading to better understanding of the photoinduced solid-solid transformation among these three As4S4 phases.\n(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized. Polymorphs of minerals Phase transitions of polymorphs Realgar-pararealgar Photoinduced solid-state transition Single-crystal X-ray photodiffraction FTIR spectroscopy Raman spectroscopy Sulfur atom migration\n### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction\nAs it was already mentioned, once very small red crystals of realgar are exposed to direct visible light, they convert slowly to a yellow powder of pararealgar, and the process continues even after they have been stored in the dark [60].\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in\nThe systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "score": 0.4454336166381836, "snippets": [{"text": "This means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).", "score": 0.5155298709869385, "metadata": {"chunk_index": 61, "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "ingest_kind": "existing_chroma", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "doi": "10.1007/s40828-019-0100-9", "year": "2020", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "This means that the fragment As2As3S4As4S3 is the half-molecule fragment that survives the transformation of realgar to pararealgar as As2As3'S4As4S3' (Fig. 7c).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "It summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy.", "score": 0.4454336166381836, "metadata": {"title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "year": "2020", "journal": "ChemTexts", "doi": "10.1007/s40828-019-0100-9", "ingest_kind": "existing_chroma", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "chunk_index": 1, "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "It summarizes the results of a detailed study of the reaction mechanism of photoinduced solid-state transformation of the mineral realgar (alpha-As4S4) to its distinct polymorph pararealgar by a combination of in situ single-crystal X-ray photodiffraction, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.", "score": 0.45685338973999023, "metadata": {"ingest_kind": "existing_chroma", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "chunk_index": 2, "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "journal": "ChemTexts", "doi": "10.1007/s40828-019-0100-9", "year": "2020", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Figure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).", "score": 0.4743976593017578, "metadata": {"source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "chunk_index": 67, "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "journal": "ChemTexts", "doi": "10.1007/s40828-019-0100-9", "ingest_kind": "existing_chroma", "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Figure 8: Temporal profiles and kinetic constants of the conversion of realgar to pararealgar induced by excitation at 1.96 eV and monitored by the reaction extent, expressed as the normalized integrated intensity of the 274 cm{}^{-1} Raman band of pararealgar (green, blue, and red marks correspond to excitation at 24.2, 10.3, and 1.5 kW/cm{}^{2}, respectively).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light ### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction", "score": 0.5056250691413879, "metadata": {"source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "ingest_kind": "existing_chroma", "doi": "10.1007/s40828-019-0100-9", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "year": "2020", "journal": "ChemTexts", "chunk_index": 42, "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light ### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Although the complete mechanism of the photoinduced transformation of realgar to pararealgar on the atomic scale has been unraveled, the interest to continue exploring the light-induced transformation in the scientific community (by means of FTIR [75; 76], Raman spectroscopy [75; 76; 77], and X-ray diffraction [75; 77]) remains. In addition, recently the multistage reverse transformation of pararealgar to both As4S4 phases (beta-As4S4 and realgar) was revealed and described by X-ray powder diffraction (XRPD) [78] leading to better understanding of the photoinduced solid-solid transformation among these three As4S4 phases.", "score": 0.5094079971313477, "metadata": {"journal": "ChemTexts", "year": "2020", "chunk_index": 35, "doi": "10.1007/s40828-019-0100-9", "ingest_kind": "existing_chroma", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Although the complete mechanism of the photoinduced transformation of realgar to pararealgar on the atomic scale has been unraveled, the interest to continue exploring the light-induced transformation in the scientific community (by means of FTIR [75; 76], Raman spectroscopy [75; 76; 77], and X-ray diffraction [75; 77]) remains. In addition, recently the multistage reverse transformation of pararealgar to both As4S4 phases (beta-As4S4 and realgar) was revealed and described by X-ray powder diffraction (XRPD) [78] leading to better understanding of the photoinduced solid-solid transformation among these three As4S4 phases.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized. Polymorphs of minerals Phase transitions of polymorphs Realgar-pararealgar Photoinduced solid-state transition Single-crystal X-ray photodiffraction FTIR spectroscopy Raman spectroscopy Sulfur atom migration", "score": null, "metadata": {"title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "ingest_kind": "existing_chroma", "doi": "10.1007/s40828-019-0100-9", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "chunk_index": 3, "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "(step 2) reacts with a molecule of realgar to produce a molecule of pararealgar (step 3), whereupon a sulfur atom is released which continues the process (step 4). The photodiffraction technique provides direct atomic resolution evidence of formation of intermediate As4S5 phase in which half of the realgar molecule retains its envelope-type conformation, while the geometry of the other half is transformed by effective switching of positions of one sulfur and one arsenic atom. The migration (hopping) of sulfur atoms between the molecules of the single crystal of realgar is observed and visualized. Polymorphs of minerals Phase transitions of polymorphs Realgar-pararealgar Photoinduced solid-state transition Single-crystal X-ray photodiffraction FTIR spectroscopy Raman spectroscopy Sulfur atom migration", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction", "score": null, "metadata": {"year": "2020", "chunk_index": 43, "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "doi": "10.1007/s40828-019-0100-9", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "ingest_kind": "existing_chroma", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "### Monitoring of the transition with Raman spectroscopy #### Irradiation by laser light Compared to the approximately 180 days required for transformation of realgar to pararealgar during sunlight irradiation, we have used the laser excitation of 632.8 nm that fits within the established 500-670 nm region [33] appropriate for the realgar-pararealgar photoconversion. By irradiation of the natural realgar, carried out by adjusting the power intensity to 10.3 kW/cm{}^{2} (although we have conducted two successful additional measurements at 1.5 and 24.2 kW/cm{}^{2}, not presented here), the photoconversion was completed in about 3 h and afforded a final Raman spectrum that fully conforms to the corresponding spectrum of pure pararealgar (Fig. 6) [47]. ### Direct observation of the transition with single-crystal X-ray photodiffraction", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "As it was already mentioned, once very small red crystals of realgar are exposed to direct visible light, they convert slowly to a yellow powder of pararealgar, and the process continues even after they have been stored in the dark [60].", "score": null, "metadata": {"year": "2020", "ingest_kind": "existing_chroma", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "chunk_index": 62, "doi": "10.1007/s40828-019-0100-9", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "As it was already mentioned, once very small red crystals of realgar are exposed to direct visible light, they convert slowly to a yellow powder of pararealgar, and the process continues even after they have been stored in the dark [60].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in", "score": null, "metadata": {"chunk_index": 73, "ingest_kind": "existing_chroma", "doi": "10.1007/s40828-019-0100-9", "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "journal": "ChemTexts", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "score": null, "metadata": {"title": "Intriguing minerals: photoinduced solid-state transition of realgar to pararealgar—direct atomic scale observation and visualization", "chunk_index": 75, "year": "2020", "source": "markdown_output/Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "source_file": "Intriguing minerals: photoinduced solid‑state transition of realgar  to pararealgar—direct atomic scale observation and visualization.md", "journal": "ChemTexts", "ingest_kind": "existing_chroma", "doi": "10.1007/s40828-019-0100-9", "authors": [{"family": "Jovanovski", "given": "Gligor"}, {"family": "Makreski", "given": "Petre"}], "volume": "6", "issue": "1", "article_number": "5", "url": "https://doi.org/10.1007/s40828-019-0100-9"}, "evidence_level": "edge_direct", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The systematic knowledge gained from the photoinduced transformation of realgar to pararealgar has implications for the conservation of minerals and their optimal storage. Namely, the destruction of realgar samples should be avoided or at least slowed down by proposing safety measures to eliminate the possibility for its solid-solid photo-transformation. Having in mind that mineral photoconversion essentially needs combination of oxygen atmosphere and visible light in the 500-670 nm region, one should prevent either the presence of oxygen or the presence of light. However, because transparent exhibition box-windows are needed to constantly monitor and observe the real mineral color of the sample by naked eye, it is recommended to either keep the realgar samples in air-evacuated (vacuum) conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both). One procedure that might overcome the light problem is placing the realgar specimens in conditions or keep the samples in an inert gas atmospheric chamber (or a subsequent combination of both).", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The Light-Induced Alteration of Realgar to Pararealgar.", "score": 0.5079103708267212, "snippets": [{"text": "The Light-Induced Alteration of Realgar to Pararealgar.", "score": 0.5079103708267212, "metadata": {"fulltext_url": "https://pure.uva.nl/ws/files/168418547/broers-et-al-2023-two-pathways-for-the-degradation-of-orpiment-pigment-_as2s3_-found-in-paintings.pdf", "year": "2023", "source_file": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "ingest_kind": "pdf_fulltext", "journal": "Journal of the American Chemical Society", "doi": "10.1021/jacs.2c12271", "title": "Two Pathways for the Degradation of Orpiment Pigment (As<sub>2</sub>S<sub>3</sub>) Found in Paintings", "source": "Two_Pathways_for_the_Degradation_of_Orpiment_Pigment_As_sub_2_sub_S_sub_3_sub_Found_in_Pai_f17328a8a073.pdf", "page": 13, "chunk_index": 36, "license": "https://creativecommons.org/licenses/by/4.0/"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The Light-Induced Alteration of Realgar to Pararealgar.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Small quantities of yellow crystalline pararealgar was obtained by natural light aging of natural realgar (Kremer Pigmente GmbH & Co, Aichstetten, Germany) while orange-red g-As40S60 was considered as reference for the amor- phous arsenic sul fide.\nAs such, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58].\nuch, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58]. Therefore, the migrated arsenic species identi fied in H1 (white line indicated by an arrow in Fig. 3) could not only be due to the degradation of the realgar crys- talline phase found in the glass pigment but can also find its origin in the degradation of the pararealgar remnants found in the amorphous material after its partial sublimation. Consequently, the presence of migrated arsenic degradation products and pararealgar does not ne- cessarily indicate a degradation of natural realgar used as primary source for the amorphous pigment. The analyzed particles in H1 are big enough (ca. 10 μm) to suppose that the center of the particle (where the Raman analyses were per- formed) has not yet been in fluenced by light.", "score": null, "snippets": [{"text": "Small quantities of yellow crystalline pararealgar was obtained by natural light aging of natural realgar (Kremer Pigmente GmbH & Co, Aichstetten, Germany) while orange-red g-As40S60 was considered as reference for the amor- phous arsenic sul fide.", "score": null, "metadata": {"title": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments", "source_file": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments.md", "year": "2018", "chunk_index": 3, "journal": "Dyes and Pigments", "doi": "10.1016/j.dyepig.2017.10.009", "source": "pdf_reextract/雄黄", "ingest_kind": "pdf_reextract"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Small quantities of yellow crystalline pararealgar was obtained by natural light aging of natural realgar (Kremer Pigmente GmbH & Co, Aichstetten, Germany) while orange-red g-As40S60 was considered as reference for the amor- phous arsenic sul fide.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "As such, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58].", "score": null, "metadata": {"journal": "Dyes and Pigments", "source_file": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments.md", "title": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments", "chunk_index": 24, "ingest_kind": "pdf_reextract", "year": "2018", "doi": "10.1016/j.dyepig.2017.10.009", "source": "pdf_reextract/雄黄"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "As such, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "uch, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58]. Therefore, the migrated arsenic species identi fied in H1 (white line indicated by an arrow in Fig. 3) could not only be due to the degradation of the realgar crys- talline phase found in the glass pigment but can also find its origin in the degradation of the pararealgar remnants found in the amorphous material after its partial sublimation. Consequently, the presence of migrated arsenic degradation products and pararealgar does not ne- cessarily indicate a degradation of natural realgar used as primary source for the amorphous pigment. The analyzed particles in H1 are big enough (ca. 10 μm) to suppose that the center of the particle (where the Raman analyses were per- formed) has not yet been in fluenced by light.", "score": null, "metadata": {"journal": "Dyes and Pigments", "year": "2018", "source": "pdf_reextract/雄黄", "title": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments", "source_file": "Identification by Raman spectroscopy of pararealgar as a starting material in the synthesis of amorphous arsenic sulfide pigments.md", "ingest_kind": "pdf_reextract", "chunk_index": 25, "doi": "10.1016/j.dyepig.2017.10.009"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "uch, arsenic oxide and pararealgar have been identi fied as degradation products of the amorphous arsenic sul- fide made from realgar [10]. However, arsenic oxide is also an expected degradation product of pararealgar itself [58]. Therefore, the migrated arsenic species identi fied in H1 (white line indicated by an arrow in Fig. 3) could not only be due to the degradation of the realgar crys- talline phase found in the glass pigment but can also find its origin in the degradation of the pararealgar remnants found in the amorphous material after its partial sublimation. Consequently, the presence of migrated arsenic degradation products and pararealgar does not ne- cessarily indicate a degradation of natural realgar used as primary source for the amorphous pigment. The analyzed particles in H1 are big enough (ca. 10 μm) to suppose that the center of the particle (where the Raman analyses were per- formed) has not yet been in fluenced by light.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Realgar on the other side, is known to degrade to pararealgar within days upon exposure to normal light levels [70].\nBefore this date, the historical sources mention that light exposed realgar forms orpiment, which led to misinterpretation and up until almost 30 years ago, the friable yellow pararealgar generally was identified as orpiment [71, 72].\nRadiation damage Pararealgar is known to be a light-induced degradation product of realgar as well as of the minerals in the alacranite (As8S9) series, both the natural and synthetic phases [2].", "score": null, "snippets": [{"text": "Realgar on the other side, is known to degrade to pararealgar within days upon exposure to normal light levels [70].", "score": null, "metadata": {"chunk_index": 7, "journal": "Heritage Science", "source_file": "s40494-024-01350-x.pdf", "ingest_kind": "pdf_direct", "doi": "10.1186/s40494-024-01350-x", "source": "pdf_direct/s40494-024-01350-x", "year": "2024", "title": "Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Realgar on the other side, is known to degrade to pararealgar within days upon exposure to normal light levels [70].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Before this date, the historical sources mention that light exposed realgar forms orpiment, which led to misinterpretation and up until almost 30 years ago, the friable yellow pararealgar generally was identified as orpiment [71, 72].", "score": null, "metadata": {"source_file": "s40494-024-01350-x.pdf", "source": "pdf_direct/s40494-024-01350-x", "title": "Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization", "journal": "Heritage Science", "year": "2024", "chunk_index": 9, "doi": "10.1186/s40494-024-01350-x", "ingest_kind": "pdf_direct"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Before this date, the historical sources mention that light exposed realgar forms orpiment, which led to misinterpretation and up until almost 30 years ago, the friable yellow pararealgar generally was identified as orpiment [71, 72].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Radiation damage Pararealgar is known to be a light-induced degradation product of realgar as well as of the minerals in the alacranite (As8S9) series, both the natural and synthetic phases [2].", "score": null, "metadata": {"source": "pdf_direct/s40494-024-01350-x", "title": "Discovery of pararealgar and semi-amorphous pararealgar in Rembrandt's The Night Watch: analytical study and historical contextualization", "chunk_index": 19, "year": "2024", "ingest_kind": "pdf_direct", "journal": "Heritage Science", "source_file": "s40494-024-01350-x.pdf", "doi": "10.1186/s40494-024-01350-x"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Radiation damage Pararealgar is known to be a light-induced degradation product of realgar as well as of the minerals in the alacranite (As8S9) series, both the natural and synthetic phases [2].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Exposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].", "score": null, "snippets": [{"text": "Exposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].", "score": null, "metadata": {"source": "On the stability of mediaeval inorganic pigments - a review", "year": "2017", "page": "16", "ingest_kind": "pdf_fulltext", "chunk_index": "53", "source_file": "On the stability of mediaeval inorganic pigments - a review", "doi": "10.1186/s40494-017-0125-6", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "journal": "Heritage Science"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "As4S4", "product": "p-As4S4", "condition": "Uv", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Exposed to (green) light, both high and low temperature realgar transform into brittle, bright yellow pararealgar [106, 177, 181], and finally to arsenic trioxide (As2O3) [106, 180, 188].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The light‐induced alteration of realgar to pararealgar.", "score": null, "snippets": [{"text": "The light‐induced alteration of realgar to pararealgar.", "score": null, "metadata": {"source_file": "On the stability of mediaeval inorganic 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pararealgar.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "realgar", "product_span": "pararealgar", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 7, "resolver_scanned": 2314, "resolver_candidates": 157, "resolver_kept": 21, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 1, "lexical_scanned": 2314, "lexical_candidates": 157, "lexical_kept": 21, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/745b0fd0119e2843e4bc83af56a23dfeb7a12f1e.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Alkaline]--> Cu(OH)2 --[Alkaline]--> [Cu(OH)4]2- --[Alkaline]--> CuO", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 2: direct\nmetastable phases that are difficult to isolate in pure crystalline form 23,43. Consequently, at room temperature and under high pH conditions, Cu(OH)2 forms a complex anion (Cu(OH)4 2−)t h a ta c t sa sap r e c u r s o ri nt h e formation of black Cu-oxides43. Although Cu-hydroxides were not identi- fied by μXRD in our samples, their formation as an intermediate phase cannot be excluded, particularly given the strongly alkaline and humid environment of frescoes. Importantly, copper hydroxides are thermodynamically unstable under ambient conditions and tend to dehy- drate or transform into copper oxides 44. In the mock-ups here evaluated, tenorite (CuO) and cuprite (Cu2O) were identified only in some samples, suggesting that hydroxides and other intermediates may evolve towards CuO over time.\n\n[2] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> CuO: direct\nis formed. The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124]. Malachite (CuCO3·Cu(OH)2, green) Malachite (CuCO 3·Cu(OH)2) is more stable than azurite (2CuCO 3·Cu(OH)2) and verdigris (xCu(CH3COO2)·yCu(OH)2·zH2O), therefore showing less or slower reactivity towards many factors [119, 123]. It is known to be permanent in all binding media, light - fast and alkali proof.\n\n[3] Evidence classification: edge 1: direct\ndesantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> CuO: direct\nConversion of azurite into tenorite (CuO) can be due to two different causes: alkaline environment and heat.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> CuO: direct\nThe azurite alteration in a black pigment, the copper oxide (tenor ite), has been studied by micro-Raman spectroscopy. The blackening can be due to thermal or chemical alte rations: in the second case the alterations being due to the presence of alkaline conditions.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> CuO: direct\ne. The authors attributed the alteration to the alkaline conditions characterizing the burial site, and due to the large presence of CaO and humidity. A recent study 10 has investigated the problem of alteration of the pigment to tenorite, related both to the painting technique and to some materials traditionally employed in conservation. Other studies consider the transformation that a mural painting can undergo after exposure to heat. 11 Rickerby12 investigated the problem of the conversion of azurite into cupric oxide caused by high temperature by reproducing painted samples and heating them to different temperature ranges.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> CuO: direct\nMicro-Raman spectroscopy turns out to be the suitable analytical technique in these cases and, as we have shown, it is possible to detect the presence of both the degraded and nondegraded forms in the same micro areas. As already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.\n\n[3] Evidence classification: pathway endpoints 2CuCO3·Cu(OH)2 -> CuO: direct\nAs already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.\n\n[4] Evidence classification: edge 1: direct\nThe treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "ref_list": ["Blackening of copper pigments in wall paintings: impact of the fresco technique and the chemical composition of the pigments [J/OL]. Heritage Science, 2026:10. DOI: 10.1038/s40494-026-02461-3. (bibliographic metadata partially available)", "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "MATTEI E, VIVO GD, SANTIS AD, et al. Raman spectroscopic analysis of azurite blackening [J/OL]. Journal of Raman Spectroscopy, 2008. DOI: 10.1002/jrs.1845.", "POZO-ANTONIO JS, CARDELL C, BARRAL D, et al. Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints [J/OL]. Minerals, 2020. DOI: 10.3390/min10050424."], "ref_snippets": [{"text": "metastable phases that are difficult to isolate in pure crystalline form 23,43. Consequently, at room temperature and under high pH conditions, Cu(OH)2 forms a complex anion (Cu(OH)4 2−)t h a ta c t sa sap r e c u r s o ri nt h e formation of black Cu-oxides43. Although Cu-hydroxides were not identi- fied by μXRD in our samples, their formation as an intermediate phase cannot be excluded, particularly given the strongly alkaline and humid environment of frescoes. Importantly, copper hydroxides are thermodynamically unstable under ambient conditions and tend to dehy- drate or transform into copper oxides 44. In the mock-ups here evaluated, tenorite (CuO) and cuprite (Cu2O) were identified only in some samples, suggesting that hydroxides and other intermediates may evolve towards CuO over time.", "score": 0.4655810594558716, "snippets": [{"text": "metastable phases that are difficult to isolate in pure crystalline form 23,43. Consequently, at room temperature and under high pH conditions, Cu(OH)2 forms a complex anion (Cu(OH)4 2−)t h a ta c t sa sap r e c u r s o ri nt h e formation of black Cu-oxides43. Although Cu-hydroxides were not identi- fied by μXRD in our samples, their formation as an intermediate phase cannot be excluded, particularly given the strongly alkaline and humid environment of frescoes. Importantly, copper hydroxides are thermodynamically unstable under ambient conditions and tend to dehy- drate or transform into copper oxides 44. In the mock-ups here evaluated, tenorite (CuO) and cuprite (Cu2O) were identified only in some samples, suggesting that hydroxides and other intermediates may evolve towards CuO over time.", "score": 0.4655810594558716, "metadata": {"source_file": "Blackening of copper pigments in wall paintings", "year": "2026", "chunk_index": "33", "page": "10", "ingest_kind": "pdf_fulltext", "source": "Blackening of copper pigments in wall paintings", "doi": "10.1038/s40494-026-02461-3", "title": "Blackening of copper pigments in wall paintings: impact of the fresco technique and the chemical composition of the pigments", "journal": "Heritage Science"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 2, "reactant": "Cu(OH)2", "product": "[Cu(OH)4]2-", "condition": "Alkaline", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "metastable phases that are difficult to isolate in pure crystalline form 23,43. Consequently, at room temperature and under high pH conditions, Cu(OH)2 forms a complex anion (Cu(OH)4 2−)t h a ta c t sa sap r e c u r s o ri nt h e formation of black Cu-oxides43. Although Cu-hydroxides were not identi- fied by μXRD in our samples, their formation as an intermediate phase cannot be excluded, particularly given the strongly alkaline and humid environment of frescoes. Importantly, copper hydroxides are thermodynamically unstable under ambient conditions and tend to dehy- drate or transform into copper oxides 44. In the mock-ups here evaluated, tenorite (CuO) and cuprite (Cu2O) were identified only in some samples, suggesting that hydroxides and other intermediates may evolve towards CuO over time.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Cu(OH)2", "product_span": "Cu(OH)4", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "is formed. The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124]. Malachite (CuCO3·Cu(OH)2, green) Malachite (CuCO 3·Cu(OH)2) is more stable than azurite (2CuCO 3·Cu(OH)2) and verdigris (xCu(CH3COO2)·yCu(OH)2·zH2O), therefore showing less or slower reactivity towards many factors [119, 123]. It is known to be permanent in all binding media, light - fast and alkali proof.", "score": 0.475486695766449, "snippets": [{"text": "is formed. The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124]. Malachite (CuCO3·Cu(OH)2, green) Malachite (CuCO 3·Cu(OH)2) is more stable than azurite (2CuCO 3·Cu(OH)2) and verdigris (xCu(CH3COO2)·yCu(OH)2·zH2O), therefore showing less or slower reactivity towards many factors [119, 123]. It is known to be permanent in all binding media, light - fast and alkali proof.", "score": 0.475486695766449, "metadata": {"year": "2017", "ingest_kind": "pdf_fulltext", "source": "On the stability of mediaeval inorganic pigments - a review", "journal": "Heritage Science", "chunk_index": "40", "doi": "10.1186/s40494-017-0125-6", "title": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments", "source_file": "On the stability of mediaeval inorganic pigments - a review", "page": "13"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Alkaline", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "is formed. The effect of laser irradiation on azurite is the formation of black CuO, which depends on the particle size and therefore on the temperature increase [112, 114, 125]. Selective biological activity is observed towards lead pigments [124]. Malachite (CuCO3·Cu(OH)2, green) Malachite (CuCO 3·Cu(OH)2) is more stable than azurite (2CuCO 3·Cu(OH)2) and verdigris (xCu(CH3COO2)·yCu(OH)2·zH2O), therefore showing less or slower reactivity towards many factors [119, 123]. It is known to be permanent in all binding media, light - fast and alkali proof.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "azurite", "product_span": "CuO", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "desantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.\nConversion of azurite into tenorite (CuO) can be due to two different causes: alkaline environment and heat.\nThe azurite alteration in a black pigment, the copper oxide (tenor ite), has been studied by micro-Raman spectroscopy. The blackening can be due to thermal or chemical alte rations: in the second case the alterations being due to the presence of alkaline conditions.\ne. The authors attributed the alteration to the alkaline conditions characterizing the burial site, and due to the large presence of CaO and humidity. A recent study 10 has investigated the problem of alteration of the pigment to tenorite, related both to the painting technique and to some materials traditionally employed in conservation. Other studies consider the transformation that a mural painting can undergo after exposure to heat. 11 Rickerby12 investigated the problem of the conversion of azurite into cupric oxide caused by high temperature by reproducing painted samples and heating them to different temperature ranges.\nMicro-Raman spectroscopy turns out to be the suitable analytical technique in these cases and, as we have shown, it is possible to detect the presence of both the degraded and nondegraded forms in the same micro areas. As already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.\nAs already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.", "score": 0.4565848112106323, "snippets": [{"text": "desantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.", "score": 0.4565848112106323, "metadata": {"year": "2008", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "title": "Raman spectroscopic analysis of azurite blackening", "chunk_index": 2, "journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.1845", "ingest_kind": "pdf_reextract", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu(OH)2", "condition": "Alkaline", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "desantis@unitus.it in 1950 by Liberti, 7 who ascribed the formation of the oxide to an altered alkalinity of the plaster. The OH- ions it releases react with the copper atoms present in the azurite molecules and form copper hydroxide, which in turn transforms into water and copper oxide.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "copper hydroxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Conversion of azurite into tenorite (CuO) can be due to two different causes: alkaline environment and heat.", "score": 0.4565848112106323, "metadata": {"year": "2008", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "title": "Raman spectroscopic analysis of azurite blackening", "chunk_index": 2, "journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.1845", "ingest_kind": "pdf_reextract", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Alkaline", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Conversion of azurite into tenorite (CuO) can be due to two different causes: alkaline environment and heat.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "tenorite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The azurite alteration in a black pigment, the copper oxide (tenor ite), has been studied by micro-Raman spectroscopy. The blackening can be due to thermal or chemical alte rations: in the second case the alterations being due to the presence of alkaline conditions.", "score": null, "metadata": {"year": "2008", "doi": "10.1002/jrs.1845", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "ingest_kind": "pdf_reextract", "chunk_index": 0, "journal": "Journal of Raman Spectroscopy", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "title": "Raman spectroscopic analysis of azurite blackening", "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Alkaline", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "The azurite alteration in a black pigment, the copper oxide (tenor ite), has been studied by micro-Raman spectroscopy. The blackening can be due to thermal or chemical alte rations: in the second case the alterations being due to the presence of alkaline conditions.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "tenorite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "e. The authors attributed the alteration to the alkaline conditions characterizing the burial site, and due to the large presence of CaO and humidity. A recent study 10 has investigated the problem of alteration of the pigment to tenorite, related both to the painting technique and to some materials traditionally employed in conservation. Other studies consider the transformation that a mural painting can undergo after exposure to heat. 11 Rickerby12 investigated the problem of the conversion of azurite into cupric oxide caused by high temperature by reproducing painted samples and heating them to different temperature ranges.", "score": null, "metadata": {"title": "Raman spectroscopic analysis of azurite blackening", "journal": "Journal of Raman Spectroscopy", "chunk_index": 3, "source_file": "Raman spectroscopic analysis of azurite blackening.md", "doi": "10.1002/jrs.1845", "ingest_kind": "pdf_reextract", "year": "2008", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Alkaline", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "e. The authors attributed the alteration to the alkaline conditions characterizing the burial site, and due to the large presence of CaO and humidity. A recent study 10 has investigated the problem of alteration of the pigment to tenorite, related both to the painting technique and to some materials traditionally employed in conservation. Other studies consider the transformation that a mural painting can undergo after exposure to heat. 11 Rickerby12 investigated the problem of the conversion of azurite into cupric oxide caused by high temperature by reproducing painted samples and heating them to different temperature ranges.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "cupric oxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Micro-Raman spectroscopy turns out to be the suitable analytical technique in these cases and, as we have shown, it is possible to detect the presence of both the degraded and nondegraded forms in the same micro areas. As already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.", "score": null, "metadata": {"ingest_kind": "pdf_reextract", "source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "year": "2008", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.1845", "title": "Raman spectroscopic analysis of azurite blackening", "chunk_index": 14, "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Alkaline", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "Micro-Raman spectroscopy turns out to be the suitable analytical technique in these cases and, as we have shown, it is possible to detect the presence of both the degraded and nondegraded forms in the same micro areas. As already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "tenorite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "As already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.", "score": null, "metadata": {"source": "pdf_reextract/蓝铜矿黑化的拉曼光谱分析", "year": "2008", "journal": "Journal of Raman Spectroscopy", "doi": "10.1002/jrs.1845", "title": "Raman spectroscopic analysis of azurite blackening", "chunk_index": 16, "ingest_kind": "pdf_reextract", "source_file": "Raman spectroscopic analysis of azurite blackening.md", "authors": [{"family": "Mattei", "given": "E."}, {"family": "de Vivo", "given": "G."}, {"family": "De Santis", "given": "A."}, {"family": "Gaetani", "given": "C."}, {"family": "Pelosi", "given": "C."}, {"family": "Santamaria", "given": "U."}], "volume": "39", "issue": "2", "pages": "302-306", "url": "https://doi.org/10.1002/jrs.1845"}, "evidence_level": "pathway_endpoint", "retrieval_origin": "crn_provenance", "retrieval_routes": ["crn_provenance", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 0, "reactant": "2CuCO3·Cu(OH)2", "product": "CuO", "condition": "Alkaline", "evidence_scope": "pathway_endpoint", "verdict": "direct", "score": 1.0, "window": "As already known, the alkalinity conditions are responsible for the degradation of azurite into tenorite.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "tenorite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "score": 0.43921202421188354, "snippets": [{"text": "The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "score": 0.43921202421188354, "metadata": {"journal": "Minerals", "ingest_kind": "pdf_direct", "source_file": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints.pdf", "chunk_index": 7, "source": "pdf_direct/min10050424_part2.pdf", "doi": "10.3390/min10050424", "year": "2020", "title": "Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "resolver", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "Cu(OH)2", "condition": "Alkaline", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The treatment of such damaged azurite tempera paints with ammonium carbonate and barium hydroxide (both well- known chemical reagents used in the restoration of mural paintings) can also yield the precipitation Minerals 2020, 10, 424 3 of 24 of black copper species such as copper hydroxide or basic copper chloride [33]. Black colored tenorite (CuO) was the final product of the reaction between malachite and azurite with alkaline solutions in laboratory conditions [34]. As regards artificial aging of azurite due to SO 2 exposure, to the knowledge of the authors, only one research study has so far been carried out. In the cited study, the effect on egg yolk-based azurite paint mock-ups of exposure to a mixture of 10.2 ppm SO 2, 11.4 ppm NO, and 5.2 ppm NO 2 was evaluated over 4 days (23 °C and 55% RH) [7]: the authors detected the formation of inorganic compounds such as nitrates (NO3−), nitrites (NO2−), and sulfates (SO42−). This work is part of a two-part research series entitled Effect of a SO 2 rich atmosphere on tempera paint mock-ups.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "copper hydroxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 29, "dense_candidates": 580, "dense_kept": 4, "resolver_scanned": 2314, "resolver_candidates": 30, "resolver_kept": 4, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 6, "lexical_scanned": 2314, "lexical_candidates": 236, "lexical_kept": 9, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/75796da0d2a956763d725df3d09c24c854f3afa9.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Chloride]--> CuCl", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["DOMÉNECH‐CARBÓ MT, EDWARDS HGM, DOMÉNECH‐CARBÓ A, et al. An authentication case study: Antonio Palomino versus Vicente Guillo paintings in the vaulted ceiling of the Sant Joan del Mercat church (Valencia, Spain) [J/OL]. Journal of Raman Spectroscopy, 2012. DOI: 10.1002/jrs.3168.", "PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1."], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "unsupported"}, {"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [{"source": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:13. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "snippet": "Page 13 of 25 Coccato et al. Herit Sci (2017) 5:12 shows good performances both in oil and tempera mediums [111, 112], although its poor hiding power in oil is reported in literature [113]. Degradation of azurite in frescoes seems related to pH and grain size [91, 114]. Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH) 2) and paratacamite/atacamite (Cu2Cl(OH) 3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu 2Cl(OH) 3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH) 2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu 2Cl(OH) 3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58]. On the other hand, oxalates attributable to the biodegrada - tion of an organic binder were found in both a gyp - sum preparation (weddellite/whewellite) and in the overlying azurite-containing paint layer [116].", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCl", "condition": "Chloride", "evidence_scope": "edge", "verdict": "qualified", "score": 0.87, "window": "Azurite degrades to green compounds: mal - achite (CuCO 3·Cu(OH)2) and paratacamite/atacamite (Cu2Cl(OH)3) are some examples [28, 64, 111, 112, 115–118]. Humidity and chloride ions from various sources cause the formation of black copper oxides (CuO) and green chlorides (nantokite CuCl, para - tacamite/atacamite or botallackite Cu2Cl(OH)3 [ 103, 116, 118–121]). Azurite degrades to black tenorite CuO when exposed to heat in presence of alkali [20, 68, 91, 103, 113, 114, 121–123], while cold alkaline conditions might not affect it [111], or cause conver - sion to malachite [119], or the formation of tenorite via formation of copper hydroxide Cu(OH)2 [ 35, 64, 114]. On the other hand, it is decomposed by acids, such as oxalic acid to form oxalates (CuC 2O4·nH2O, mooloite) [32, 55, 116]. It has been reported that the combination of oxalic acid and chlorides in wall paintings results in Cu-hydroxychlorides Cu2Cl(OH)3 and Ca-oxalates [59]; and that no Cu-oxalates were observed in azurite paint layers [58].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "nantokite", "relation_basis": "product_identification", "condition_status": "exact", "provenance_level": "unspecified", "reasons": ["relation_product_identification"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "PURDY EH, CRITCHLEY S, HOLÉ C, et al. Characterisation of rouaite, an unusual copper-containing pigment in early modern English wall paintings, by synchrotron micro X-Ray diffraction and micro X-Ray absorption spectroscopy [J/OL]. Applied Physics A, 2024. DOI: 10.1007/s00339-024-07954-1.", "snippet": "Characterisation of rouaite, an unusual copper‐containing pigment in early modern English... Page 15 of 18 817 suggests that formation of nantokite (CuCl) may occur as an intermediate reaction in the formation of copper hydroxychlorides (Equation 3) [80]. The reactions presented here therefore offer plausible routes for azurite as well as rouaite degradation, but further study is needed to determine whether intermediate species are indeed formed and the relative favourability. Rouaite’s metastability and propensity to react further is a possible explanation for its absence in literature. Apart from degradation or conversion to other copper minerals such as chlorides or sulfates, identification of rouaite in historical samples may be hampered by the difficulty of detecting light elements such as nitrogen, the low abundance in some samples necessitating analysis with a low detection limit, and the similarity of rouaite to synthetic malachite, copper chlorides, and verditer when examined by optical and scanning electron microscopy. 4 Conclusion Rouaite, a basic copper nitrate found to be a significant byproduct of the refiners’ synthesis of blue verditer, has been identified in historical wall painting samples for the first time to our knowledge. Table 2 presents a summary of the analytic results for both samples studied. In two samples, M9 and T1, we detected rouaite using SR-/u1D707PXRD and SR-/u1D707XANES. We show that its polymorph, gerhardtite, fits the experimental data collected more poorly; this is therefore highly suggestive of a synthetic origin for the material [27]", "retrieval_origin": "crn_provenance", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCl", "condition": "Chloride", "evidence_scope": "edge", "verdict": "qualified", "score": 0.87, "window": "Characterisation of rouaite, an unusual copper‐containing pigment in early modern English... Page 15 of 18 817 suggests that formation of nantokite (CuCl) may occur as an intermediate reaction in the formation of copper hydroxychlorides (Equation 3) [80]. The reactions presented here therefore offer plausible routes for azurite as well as rouaite degradation, but further study is needed to determine whether intermediate species are indeed formed and the relative favourability. Rouaite’s metastability and propensity to react further is a possible explanation for its absence in literature. Apart from degradation or conversion to other copper minerals such as chlorides or sulfates, identification of rouaite in historical samples may be hampered by the difficulty of detecting light elements such as nitrogen, the low abundance in some samples necessitating analysis with a low detection limit, and the similarity of rouaite to synthetic malachite, copper chlorides, and verditer when examined by optical and scanning electron microscopy.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "nantokite", "relation_basis": "product_identification", "condition_status": "exact", "provenance_level": "unspecified", "reasons": ["relation_product_identification"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}, {"source": "On the stability of mediaeval inorganic pigments: a literature review of the effect of climate, material selection, biological activity, analysis and conservation treatments [J/OL]. Heritage Science, 2017:12. DOI: 10.1186/s40494-017-0125-6. (bibliographic metadata partially available)", "snippet": "In glue binder, the role of humidity and airborne pollutants in accelerating glassy pigments degradation was demonstrated, where leaching of both potassium and cobalt ions occurred. No evident effect of SO 2 and NO x synergy was observed though [87]. In fresco wall paint - ings, smalt is expected to deteriorate due to the very alka- line conditions, to the presence of liquid water (including condensation, capillary rise and infiltrations), to the small particle size increasing the surface reaction, and to the possible contamination by pollutants. Again, leaching of alkali is observed, and in some strongly degraded smalt particles showing cracks, cobalt and other divalent ions are leached as well, probably due to aggressive environ - mental conditions (humidity, basic pH) [88, 91, 96]. On top of ions lixiviation and weathering of the glass, exam - ples of heat degraded smalt are reported in wall paintings affected by fire [103]. Copper (Z = 29) It was recently observed that historical copper-based pigments are not only limited to malachite, azurite, verdigris and copper resinate. In fact a variety of salts (organic acids salts such as copper citrate [104], silicates, phosphates, sulphates, chlorides, etc.) were as well used as pigments [105, 106], and should not be regarded any - more as degradation products only. Moreover, the situa - tion is complicated by inconsistent nomenclature use in artistic literature [1, 105]. It is well known that malachite and azurite are not stable in fresco, and that they tend to discolour in oil [50].", "retrieval_origin": "bge_m3", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuCl", "condition": "Chloride", "evidence_scope": "edge", "verdict": "unsupported", "score": 0.62, "window": "Copper (Z = 29) It was recently observed that historical copper-based pigments are not only limited to malachite, azurite, verdigris and copper resinate. In fact a variety of salts (organic acids salts such as copper citrate [104], silicates, phosphates, sulphates, chlorides, etc.) were as well used as pigments [105, 106], and should not be regarded any - more as degradation products only.", "reactant_match": "alias", "product_match": "missing", "reactant_span": "azurite", "product_span": "", "relation_basis": "product_identification", "condition_status": "exact", "provenance_level": "unspecified", "reasons": ["product_missing", "relation_product_identification"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 3, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 218, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/77d5e3e65f308819ecaa7ffc184490c95d15105c.json

@@ -0,0 +1 @@
+{"root_material": "Pb3O4", "path_str": "Pb3O4 --[Oxidant]--> β-PbO2", "signature": "docs=2314", "evidence": {"context_str": "[1] Evidence classification: edge 1: direct\nThis energy shift provides direct evidence of the chemical transformation from Pb3O4 to PbO2 during the radical-mediated oxidation process. To quantitatively analyze this conversion, peak deconvolution was performed on the Pb 4f spectra at different reaction intervals. The spectral components were assigned to either Pb3O4 (137.7/142.7 eV) or PbO2 (137.0/142.0 eV) through Gaussian-Lorentzian curve fitting, as presented in Figure 4b-f. The progressive enhancement of PbO2-associated peak intensities (137.0 eV and 142.0 eV) relative to the diminishing Pb3O4 components demonstrates a time-dependent increase in PbO2 formation. This observation aligns with the hypothesis that superoxide radicals facilitate the oxidation of Pb (II) in Pb3O4 to Pb (IV) in PbO2 through electron transfer processes.\n\n[1] Evidence classification: edge 1: direct\nThe quantitative correlation between reaction duration and PbO2/Pb3O4 ratio, as revealed by peak area analysis, further confirms the gradual conversion mechanism. The systematic transition in Pb oxidation states provides spectroscopic evidence for the formation of PbO2 as the primary product in the superoxide-mediated oxidation of Pb3O4.\n\n[1] Evidence classification: edge 1: direct\nThese trends are consistent with the stoichiometric transformation from Pb3O4 to PbO2, related to the oxidation of Pb3O4.\n\n[1] Evidence classification: edge 1: direct\nThese ratios indicate a progressive decrease in both atomic and mass ratios of Pb to O during the conversion from Pb3O4 to PbO2. Furthermore, the mixed oxidation states of Pb in Pb3O4 comprise Pb (II) and Pb (IV) in a 2:1 ratio, while PbO2 exclusively contains Pb (IV) species.\n\n[1] Evidence classification: edge 1: direct\nThe temporal evolution of these spectral characteristics provides compelling evidence of the gradual chemical transformation from Pb3O4 to PbO2 with prolonged reaction duration. This experimental observation aligns well with the proposed reaction mechanism that Pb3O4 serves as the precursor material undergoing oxidative conversion to PbO2.\n\n[1] Evidence classification: edge 1: direct\n## 4 Conclusions It has been demonstrated that the reaction of Pb3O4 with superoxide radicals over varying durations produces the mixtures of partially oxidized Pb3O4 and PbO2 in distinct ratios. The singlet oxygen and superoxide radical made the main contribution to Pb3O4 oxidation under the experimental conditions.\n\n[1] Evidence classification: edge 1: direct\nOver extended temporal scales, these radicals continuously react with the red lead pigments through oxidation mechanisms, ultimately resulting in the observed blackened lead dioxide formations seen in historical artifacts.\n\n[2] Evidence classification: edge 1: direct\nLead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.\n\n[3] Evidence classification: edge 1: direct\nThe darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].\n\n[3] Evidence classification: edge 1: direct\nThe transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59].\n\n[4] Evidence classification: edge 1: direct\nNo oxidation took place except for red lead, which turns into plattnerite independently of the salt used.[14] In order to accelerate the degradation process of lead white, two strong oxidants were used: commercial NaClO and H2O2.\n\n[5] Evidence classification: edge 1: direct\nThe sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound. As an oxidising agent, PbO2 should be highly susceptible to the reducing power of H2S, but in red lead, the structure consists of chains of PbIVO6 edge-sharing octahedra linked pyramidally to each other by Pb(II) atoms [11, 12].\n\n[6] Evidence classification: edge 1: direct\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\n\n[6] Evidence classification: edge 1: direct\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34]. Scrutinyite was also not used as a pigment. The presence of hydrocerussite and creussite in the wall paintings in Saint George church could indicate that the lead white pigment originally used had converted to plattnerite, the evidence for this being that no red lead was found. But, as we found earlier, strong oxidizing agents, are necessary to enable this conversion. On the other hand, red lead darkening was found as the most common reaction of red lead in our laboratory experiments and it is possible and probable that during hundreds of years its conversion to plattnerite and creussite was total.\n\n[6] Evidence classification: edge 1: direct\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite\n\n[6] Evidence classification: edge 1: direct\nPhase abbreviations: Ca: calcite (CaCO3); Ce: cervasite (PbCO3); H: hydrocervasite (Pb9(CO3)2(OH)2); L: PbMg(CO3)2; P: plattrerite (PbO2). Figure 7: X-ray pattern of reaction product of red lead pigment with solution of MgSO4 and (NH4)2CO3. The reaction mixture reacted for six months. Phase abbreviations: Ce: cervasite (PbCO3); L: PbMg(CO3)2; M: minimum (Pb3O4); P: plattrerite (PbO2). Lead white (hydrocerussite) darkened immediately when in contact with a solution of NaClO due to its oxidation to brown-black plattrerite (PbO2).", "ref_list": ["ZHANG Z, HUANG Q, SUN J, et al. Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions [J/OL]. Molecules, 2025. DOI: 10.3390/molecules30102136.", "ZHAO Y, WANG J, PAN A, et al. Degradation of red lead pigment in the oil painting during UV aging [J/OL]. Color Research & Application, 2019. DOI: 10.1002/col.22386.", "AZE S, VALLET JM, DETALLE V, et al. Chromatic alterations of red lead pigments in artworks: a review [J/OL]. Phase Transitions, 2008. DOI: 10.1080/01411590701514326.", "VAGNINI M, VIVANI R, SGAMELLOTTI A, et al. Blackening of lead white: Study of model paintings [J/OL]. Journal of Raman Spectroscopy, 2020. DOI: 10.1002/jrs.5879.", "SMITH GD, CLARK RJH. The role of H2S in pigment blackening [J/OL]. Journal of Cultural Heritage, 2002. DOI: 10.1016/s1296-2074(02)01173-1.", "KOTULANOVÁ E, BEZDIČKA P, HRADIL D, et al. Degradation of lead-based pigments by salt solutions [J/OL]. Journal of Cultural Heritage, 2009. DOI: 10.1016/j.culher.2008.11.001."], "ref_snippets": [{"text": "This energy shift provides direct evidence of the chemical transformation from Pb3O4 to PbO2 during the radical-mediated oxidation process. To quantitatively analyze this conversion, peak deconvolution was performed on the Pb 4f spectra at different reaction intervals. The spectral components were assigned to either Pb3O4 (137.7/142.7 eV) or PbO2 (137.0/142.0 eV) through Gaussian-Lorentzian curve fitting, as presented in Figure 4b-f. The progressive enhancement of PbO2-associated peak intensities (137.0 eV and 142.0 eV) relative to the diminishing Pb3O4 components demonstrates a time-dependent increase in PbO2 formation. This observation aligns with the hypothesis that superoxide radicals facilitate the oxidation of Pb (II) in Pb3O4 to Pb (IV) in PbO2 through electron transfer processes.\nThe quantitative correlation between reaction duration and PbO2/Pb3O4 ratio, as revealed by peak area analysis, further confirms the gradual conversion mechanism. The systematic transition in Pb oxidation states provides spectroscopic evidence for the formation of PbO2 as the primary product in the superoxide-mediated oxidation of Pb3O4.\nThese trends are consistent with the stoichiometric transformation from Pb3O4 to PbO2, related to the oxidation of Pb3O4.\nThese ratios indicate a progressive decrease in both atomic and mass ratios of Pb to O during the conversion from Pb3O4 to PbO2. Furthermore, the mixed oxidation states of Pb in Pb3O4 comprise Pb (II) and Pb (IV) in a 2:1 ratio, while PbO2 exclusively contains Pb (IV) species.\nThe temporal evolution of these spectral characteristics provides compelling evidence of the gradual chemical transformation from Pb3O4 to PbO2 with prolonged reaction duration. This experimental observation aligns well with the proposed reaction mechanism that Pb3O4 serves as the precursor material undergoing oxidative conversion to PbO2.\n## 4 Conclusions It has been demonstrated that the reaction of Pb3O4 with superoxide radicals over varying durations produces the mixtures of partially oxidized Pb3O4 and PbO2 in distinct ratios. The singlet oxygen and superoxide radical made the main contribution to Pb3O4 oxidation under the experimental conditions.\nOver extended temporal scales, these radicals continuously react with the red lead pigments through oxidation mechanisms, ultimately resulting in the observed blackened lead dioxide formations seen in historical artifacts.", "score": 0.3482212424278259, "snippets": [{"text": "This energy shift provides direct evidence of the chemical transformation from Pb3O4 to PbO2 during the radical-mediated oxidation process. To quantitatively analyze this conversion, peak deconvolution was performed on the Pb 4f spectra at different reaction intervals. The spectral components were assigned to either Pb3O4 (137.7/142.7 eV) or PbO2 (137.0/142.0 eV) through Gaussian-Lorentzian curve fitting, as presented in Figure 4b-f. The progressive enhancement of PbO2-associated peak intensities (137.0 eV and 142.0 eV) relative to the diminishing Pb3O4 components demonstrates a time-dependent increase in PbO2 formation. This observation aligns with the hypothesis that superoxide radicals facilitate the oxidation of Pb (II) in Pb3O4 to Pb (IV) in PbO2 through electron transfer processes.", "score": 0.45448803901672363, "metadata": {"ingest_kind": "existing_chroma", "journal": "Molecules", "doi": "10.3390/molecules30102136", "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "year": "2025", "title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "chunk_index": 33, "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "This energy shift provides direct evidence of the chemical transformation from Pb3O4 to PbO2 during the radical-mediated oxidation process. To quantitatively analyze this conversion, peak deconvolution was performed on the Pb 4f spectra at different reaction intervals. The spectral components were assigned to either Pb3O4 (137.7/142.7 eV) or PbO2 (137.0/142.0 eV) through Gaussian-Lorentzian curve fitting, as presented in Figure 4b-f. The progressive enhancement of PbO2-associated peak intensities (137.0 eV and 142.0 eV) relative to the diminishing Pb3O4 components demonstrates a time-dependent increase in PbO2 formation. This observation aligns with the hypothesis that superoxide radicals facilitate the oxidation of Pb (II) in Pb3O4 to Pb (IV) in PbO2 through electron transfer processes.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Pb3O4", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The quantitative correlation between reaction duration and PbO2/Pb3O4 ratio, as revealed by peak area analysis, further confirms the gradual conversion mechanism. The systematic transition in Pb oxidation states provides spectroscopic evidence for the formation of PbO2 as the primary product in the superoxide-mediated oxidation of Pb3O4.", "score": 0.45488297939300537, "metadata": {"year": "2025", "doi": "10.3390/molecules30102136", "chunk_index": 34, "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "ingest_kind": "existing_chroma", "journal": "Molecules", "title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The quantitative correlation between reaction duration and PbO2/Pb3O4 ratio, as revealed by peak area analysis, further confirms the gradual conversion mechanism. The systematic transition in Pb oxidation states provides spectroscopic evidence for the formation of PbO2 as the primary product in the superoxide-mediated oxidation of Pb3O4.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Pb3O4", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "These trends are consistent with the stoichiometric transformation from Pb3O4 to PbO2, related to the oxidation of Pb3O4.", "score": 0.45956385135650635, "metadata": {"ingest_kind": "existing_chroma", "doi": "10.3390/molecules30102136", "chunk_index": 42, "title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "journal": "Molecules", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "year": "2025", "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "These trends are consistent with the stoichiometric transformation from Pb3O4 to PbO2, related to the oxidation of Pb3O4.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Pb3O4", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "These ratios indicate a progressive decrease in both atomic and mass ratios of Pb to O during the conversion from Pb3O4 to PbO2. Furthermore, the mixed oxidation states of Pb in Pb3O4 comprise Pb (II) and Pb (IV) in a 2:1 ratio, while PbO2 exclusively contains Pb (IV) species.", "score": 0.4636874794960022, "metadata": {"title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "ingest_kind": "existing_chroma", "journal": "Molecules", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "doi": "10.3390/molecules30102136", "year": "2025", "chunk_index": 39, "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "These ratios indicate a progressive decrease in both atomic and mass ratios of Pb to O during the conversion from Pb3O4 to PbO2. Furthermore, the mixed oxidation states of Pb in Pb3O4 comprise Pb (II) and Pb (IV) in a 2:1 ratio, while PbO2 exclusively contains Pb (IV) species.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Pb3O4", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The temporal evolution of these spectral characteristics provides compelling evidence of the gradual chemical transformation from Pb3O4 to PbO2 with prolonged reaction duration. This experimental observation aligns well with the proposed reaction mechanism that Pb3O4 serves as the precursor material undergoing oxidative conversion to PbO2.", "score": 0.4752335548400879, "metadata": {"year": "2025", "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "chunk_index": 38, "doi": "10.3390/molecules30102136", "ingest_kind": "existing_chroma", "journal": "Molecules", "title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The temporal evolution of these spectral characteristics provides compelling evidence of the gradual chemical transformation from Pb3O4 to PbO2 with prolonged reaction duration. This experimental observation aligns well with the proposed reaction mechanism that Pb3O4 serves as the precursor material undergoing oxidative conversion to PbO2.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Pb3O4", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "## 4 Conclusions It has been demonstrated that the reaction of Pb3O4 with superoxide radicals over varying durations produces the mixtures of partially oxidized Pb3O4 and PbO2 in distinct ratios. The singlet oxygen and superoxide radical made the main contribution to Pb3O4 oxidation under the experimental conditions.", "score": 0.4973753094673157, "metadata": {"chunk_index": 52, "ingest_kind": "existing_chroma", "journal": "Molecules", "year": "2025", "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "doi": "10.3390/molecules30102136", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "## 4 Conclusions It has been demonstrated that the reaction of Pb3O4 with superoxide radicals over varying durations produces the mixtures of partially oxidized Pb3O4 and PbO2 in distinct ratios. The singlet oxygen and superoxide radical made the main contribution to Pb3O4 oxidation under the experimental conditions.", "reactant_match": "exact", "product_match": "exact", "reactant_span": "Pb3O4", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Over extended temporal scales, these radicals continuously react with the red lead pigments through oxidation mechanisms, ultimately resulting in the observed blackened lead dioxide formations seen in historical artifacts.", "score": 0.3482212424278259, "metadata": {"ingest_kind": "existing_chroma", "source": "markdown_output/Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "title": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions", "journal": "Molecules", "year": "2025", "chunk_index": 49, "source_file": "Aging and Discoloration of Red Lead (Pb3O4) Caused by Reactive Oxygen Species Under Alkaline Conditions.md", "doi": "10.3390/molecules30102136", "authors": [{"family": "Zhang", "given": "Zhehan"}, {"family": "Huang", "given": "Qin"}, {"family": "Sun", "given": "Jiaxing"}, {"family": "Hao", "given": "Qilong"}, {"family": "Zhang", "given": "Wenyuan"}, {"family": "Yu", "given": "Zongren"}, {"family": "Su", "given": "Bomin"}, {"family": "Zhang", "given": "Haixia"}], "volume": "30", "issue": "10", "pages": "2136", "url": "https://doi.org/10.3390/molecules30102136"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "crn_provenance", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Over extended temporal scales, these radicals continuously react with the red lead pigments through oxidation mechanisms, ultimately resulting in the observed blackened lead dioxide formations seen in historical artifacts.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "lead dioxide", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Lead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.", "score": 0.5008012056350708, "snippets": [{"text": "Lead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.", "score": 0.5008012056350708, "metadata": {"source": "markdown_output/Degradation of red lead pigment in the oil painting during UV aging.md", "ingest_kind": "existing_chroma", "doi": "10.1002/col.22386", "journal": "Color Research & Application", "chunk_index": 35, "title": "Degradation of red lead pigment in the oil painting during UV aging", "source_file": "Degradation of red lead pigment in the oil painting during UV aging.md", "year": "2019"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "lexical", "resolver", "bm25"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Lead (Pb) has four valence electrons distributed in 6s orbital and 6p orbitals and Pb3O4 is made of PbO2 and PbO; therefore, minium pigment contains both Pb(II) and Pb(IV) oxides, but only Pb(II) can absorb ultraviolet light energy to form an excitation state with high energy, which makes Pb(II) lose the lone pair electrons in the 6s orbital to form Pb(IV) and then oxidize to black beta-PbO2 by ozone (oxygen ionization under ultraviolet radiation) or oxygen.", "reactant_match": "alias", "product_match": "exact", "reactant_span": "minium", "product_span": "beta-PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].\nThe transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59].", "score": 0.5071769952774048, "snippets": [{"text": "The darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].", "score": 0.5071769952774048, "metadata": {"year": "2008", "doi": "10.1080/01411590701514326", "title": "Chromatic alterations of red lead pigments in artworks: a review", "chunk_index": 18, "source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md", "journal": "Phase Transitions", "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The darkening of red lead containing paintings from antique Chinese wall paintings has been attributed to the pigment oxidation into plattnerite by microbial activity [69].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "The transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59].", "score": null, "metadata": {"year": "2008", "source_file": "Chromatic alterations of red lead pigments in artworks: a review.md", "title": "Chromatic alterations of red lead pigments in artworks: a review", "source": "markdown_output/Chromatic alterations of red lead pigments in artworks: a review.md", "chunk_index": 14, "ingest_kind": "existing_chroma", "journal": "Phase Transitions", "doi": "10.1080/01411590701514326"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The transformation of red lead into black lead dioxide (beta-PbO2, plattnerite), however, is generally stated as the main cause of red lead darkening in paintings. This compound was identified on numerous artworks, such as polychrome sculptures [8] and wall paintings [56, 57, 58]. The hypothesis of red lead oxidation into plattnerite is commonly invoked when darkened sample analyses are inefficient [59].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "red lead", "product_span": "beta-PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "No oxidation took place except for red lead, which turns into plattnerite independently of the salt used.[14] In order to accelerate the degradation process of lead white, two strong oxidants were used: commercial NaClO and H2O2.", "score": 0.470892071723938, "snippets": [{"text": "No oxidation took place except for red lead, which turns into plattnerite independently of the salt used.[14] In order to accelerate the degradation process of lead white, two strong oxidants were used: commercial NaClO and H2O2.", "score": 0.470892071723938, "metadata": {"journal": "Journal of Raman Spectroscopy", "source_file": "Blackening of lead white: Study of model paintings.md", "doi": "10.1002/jrs.5879", "year": "2020", "ingest_kind": "existing_chroma", "title": "Blackening of lead white: Study of model paintings", "source": "markdown_output/Blackening of lead white: Study of model paintings.md", "chunk_index": 3}, "evidence_level": "edge_direct", "retrieval_origin": "bge_m3", "retrieval_routes": ["bge_m3", "resolver", "lexical", "bm25"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "No oxidation took place except for red lead, which turns into plattnerite independently of the salt used.[14] In order to accelerate the degradation process of lead white, two strong oxidants were used: commercial NaClO and H2O2.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "The sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound. As an oxidising agent, PbO2 should be highly susceptible to the reducing power of H2S, but in red lead, the structure consists of chains of PbIVO6 edge-sharing octahedra linked pyramidally to each other by Pb(II) atoms [11, 12].", "score": null, "snippets": [{"text": "The sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound. As an oxidising agent, PbO2 should be highly susceptible to the reducing power of H2S, but in red lead, the structure consists of chains of PbIVO6 edge-sharing octahedra linked pyramidally to each other by Pb(II) atoms [11, 12].", "score": null, "metadata": {"source": "markdown_output/The role of H2S in pigment blackening.md", "year": "2002", "source_file": "The role of H2S in pigment blackening.md", "journal": "Journal of Cultural Heritage", "title": "The role of H2S in pigment blackening", "doi": "10.1016/s1296-2074(02)01173-1", "ingest_kind": "existing_chroma", "chunk_index": 22}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "The sluggish reaction of red lead when exposed to H2S reveals that a modest degree of protection is offered to the component PbO and PbO2 moieties by the crystal structure of this compound. As an oxidising agent, PbO2 should be highly susceptible to the reducing power of H2S, but in red lead, the structure consists of chains of PbIVO6 edge-sharing octahedra linked pyramidally to each other by Pb(II) atoms [11, 12].", "reactant_match": "alias", "product_match": "exact", "reactant_span": "red lead", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}, {"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].\nLead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34]. Scrutinyite was also not used as a pigment. The presence of hydrocerussite and creussite in the wall paintings in Saint George church could indicate that the lead white pigment originally used had converted to plattnerite, the evidence for this being that no red lead was found. But, as we found earlier, strong oxidizing agents, are necessary to enable this conversion. On the other hand, red lead darkening was found as the most common reaction of red lead in our laboratory experiments and it is possible and probable that during hundreds of years its conversion to plattnerite and creussite was total.\nBased on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite\nPhase abbreviations: Ca: calcite (CaCO3); Ce: cervasite (PbCO3); H: hydrocervasite (Pb9(CO3)2(OH)2); L: PbMg(CO3)2; P: plattrerite (PbO2). Figure 7: X-ray pattern of reaction product of red lead pigment with solution of MgSO4 and (NH4)2CO3. The reaction mixture reacted for six months. Phase abbreviations: Ce: cervasite (PbCO3); L: PbMg(CO3)2; M: minimum (Pb3O4); P: plattrerite (PbO2). Lead white (hydrocerussite) darkened immediately when in contact with a solution of NaClO due to its oxidation to brown-black plattrerite (PbO2).", "score": null, "snippets": [{"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "score": null, "metadata": {"title": "Degradation of lead-based pigments by salt solutions", "year": "2009", "doi": "10.1016/j.culher.2008.11.001", "source_file": "Degradation of lead-based pigments by salt solutions.md", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "chunk_index": 42, "journal": "Journal of Cultural Heritage", "ingest_kind": "existing_chroma"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34].", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34]. Scrutinyite was also not used as a pigment. The presence of hydrocerussite and creussite in the wall paintings in Saint George church could indicate that the lead white pigment originally used had converted to plattnerite, the evidence for this being that no red lead was found. But, as we found earlier, strong oxidizing agents, are necessary to enable this conversion. On the other hand, red lead darkening was found as the most common reaction of red lead in our laboratory experiments and it is possible and probable that during hundreds of years its conversion to plattnerite and creussite was total.", "score": null, "metadata": {"year": "2009", "title": "Degradation of lead-based pigments by salt solutions", "chunk_index": 43, "ingest_kind": "existing_chroma", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "doi": "10.1016/j.culher.2008.11.001", "source_file": "Degradation of lead-based pigments by salt solutions.md", "journal": "Journal of Cultural Heritage"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Lead white and red lead altered to plattnerite has been noted by many authors [13, 14, 34]. Scrutinyite was also not used as a pigment. The presence of hydrocerussite and creussite in the wall paintings in Saint George church could indicate that the lead white pigment originally used had converted to plattnerite, the evidence for this being that no red lead was found. But, as we found earlier, strong oxidizing agents, are necessary to enable this conversion. On the other hand, red lead darkening was found as the most common reaction of red lead in our laboratory experiments and it is possible and probable that during hundreds of years its conversion to plattnerite and creussite was total.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "score": null, "metadata": {"chunk_index": 44, "journal": "Journal of Cultural Heritage", "source_file": "Degradation of lead-based pigments by salt solutions.md", "doi": "10.1016/j.culher.2008.11.001", "year": "2009", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md", "ingest_kind": "existing_chroma", "title": "Degradation of lead-based pigments by salt solutions"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "adjacent_chunks_same_doi", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 0.8, "window": "Based on all these results, we concluded that the original pigment used for the now darkened parts of the wall paintings was red lead, which had completely transformed to plattnerite", "reactant_match": "alias", "product_match": "alias", "reactant_span": "red lead", "product_span": "plattnerite", "relation_basis": "observed_conversion", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": []}]}, {"text": "Phase abbreviations: Ca: calcite (CaCO3); Ce: cervasite (PbCO3); H: hydrocervasite (Pb9(CO3)2(OH)2); L: PbMg(CO3)2; P: plattrerite (PbO2). Figure 7: X-ray pattern of reaction product of red lead pigment with solution of MgSO4 and (NH4)2CO3. The reaction mixture reacted for six months. Phase abbreviations: Ce: cervasite (PbCO3); L: PbMg(CO3)2; M: minimum (Pb3O4); P: plattrerite (PbO2). Lead white (hydrocerussite) darkened immediately when in contact with a solution of NaClO due to its oxidation to brown-black plattrerite (PbO2).", "score": null, "metadata": {"title": "Degradation of lead-based pigments by salt solutions", "year": "2009", "chunk_index": 53, "source_file": "Degradation of lead-based pigments by salt solutions.md", "ingest_kind": "existing_chroma", "journal": "Journal of Cultural Heritage", "doi": "10.1016/j.culher.2008.11.001", "source": "markdown_output/Degradation of lead-based pigments by salt solutions.md"}, "evidence_level": "edge_direct", "retrieval_origin": "resolver", "retrieval_routes": ["resolver", "lexical"], "evidence_aggregation": "single_fragment", "edge_matches": [{"edge_index": 1, "reactant": "Pb3O4", "product": "beta-PbO2", "condition": "Oxidant", "evidence_scope": "edge", "verdict": "direct", "score": 1.0, "window": "Phase abbreviations: Ca: calcite (CaCO3); Ce: cervasite (PbCO3); H: hydrocervasite (Pb9(CO3)2(OH)2); L: PbMg(CO3)2; P: plattrerite (PbO2). Figure 7: X-ray pattern of reaction product of red lead pigment with solution of MgSO4 and (NH4)2CO3. The reaction mixture reacted for six months. Phase abbreviations: Ce: cervasite (PbCO3); L: PbMg(CO3)2; M: minimum (Pb3O4); P: plattrerite (PbO2). Lead white (hydrocerussite) darkened immediately when in contact with a solution of NaClO due to its oxidation to brown-black plattrerite (PbO2).", "reactant_match": "alias", "product_match": "exact", "reactant_span": "red lead", "product_span": "PbO2", "relation_basis": "observed_conversion", "condition_status": "exact", "provenance_level": "unspecified", "reasons": []}]}]}], "related_context": [], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 10, "resolver_scanned": 2314, "resolver_candidates": 64, "resolver_kept": 16, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 9, "lexical_scanned": 2314, "lexical_candidates": 209, "lexical_kept": 16, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}

rag_report_cache/873a843f9a7abe55bc17f3ccb7ab99552af1f96d.json

@@ -0,0 +1 @@
+{"root_material": "2CuCO3·Cu(OH)2", "path_str": "2CuCO3·Cu(OH)2 --[Binder]--> CuC2O4", "signature": "docs=2314", "evidence": {"context_str": "No relevant literature evidence was retrieved from the vector database.", "ref_list": ["LLUVERAS A, BOULARAND S, ANDREOTTI A, et al. Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR [J/OL]. Applied Physics A, 2010. DOI: 10.1007/s00339-010-5673-5."], "ref_snippets": [{"text": "", "score": null, "snippets": [], "provenance_only": true, "best_verdict": "qualified"}], "related_context": [{"source": "LLUVERAS A, BOULARAND S, ANDREOTTI A, et al. Degradation of azurite in mural paintings: distribution of copper carbonate, chlorides and oxalates by SRFTIR [J/OL]. Applied Physics A, 2010. DOI: 10.1007/s00339-010-5673-5.", "snippet": "###### Abstract This article illustrates the analysis by synchrotron micro-analytical techniques of an azurite painting presenting greenish chromatic degradation. The challenge of the experiments was to obtain the spatial distribution of the degradation products of azurite. Copper hydroxchlorides, carbonates and copper oxalates have been mapped by SR FTIR imaging of cross sections in transmission mode. To complement the information, Py/GC/MS and GC/MS techniques were applied in order to characterize the binding media and organic materials present as well as their degradation products. Results contribute to a better understanding of the decay of blue areas in ancient paintings not only from the particular point of view of azurite weathering, but also by adding information regarding the oxalates' formation and their distribution in painting samples. Synchrotron radiation demonstrates its capability for the mapping in painting cross sections.", "retrieval_origin": "crn_provenance", "match": {"edge_index": 1, "reactant": "2CuCO3·Cu(OH)2", "product": "CuC2O4", "condition": "Binder", "evidence_scope": "edge", "verdict": "qualified", "score": 0.67, "window": "The challenge of the experiments was to obtain the spatial distribution of the degradation products of azurite. Copper hydroxchlorides, carbonates and copper oxalates have been mapped by SR FTIR imaging of cross sections in transmission mode. To complement the information, Py/GC/MS and GC/MS techniques were applied in order to characterize the binding media and organic materials present as well as their degradation products.", "reactant_match": "alias", "product_match": "alias", "reactant_span": "azurite", "product_span": "copper oxalates", "relation_basis": "product_identification", "condition_status": "exact_document", "provenance_level": "unspecified", "reasons": ["relation_product_identification"]}, "reason": "Retrieved as chemically related context, but it does not directly establish this graph edge."}], "retrieval_trace": {"query_count": 12, "dense_candidates": 240, "dense_kept": 0, "resolver_scanned": 2314, "resolver_candidates": 12, "resolver_kept": 0, "bm25_scanned": 2314, "bm25_candidates": 100, "bm25_kept": 0, "lexical_scanned": 2314, "lexical_candidates": 253, "lexical_kept": 0, "strategy": "four-route retrieval (resolver + BM25 + lexical + BGE-M3) with chemical evidence gating"}}}