<?xml version="1.0" encoding="utf-8"?><metadata xmlns:dc="http://purl.org/dc/elements/1.1/"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dcterms="http://purl.org/dc/terms/"><dc:title xml:lang="en">thaumasite</dc:title><dc:identifier>http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31344601</dc:identifier><dc:language>en</dc:language><dc:publisher xml:lang="en">Getty Institute</dc:publisher><dcterms:created>2026-03-30 20:32:56</dcterms:created><dcterms:isPartOf xsi:type="dcterms:URI">http://AATesaurus.cultura.gencat.cat/aat/getty_en</dcterms:isPartOf><dcterms:isPartOf xml:lang="en">Tesaurus d&apos;Art i Arquitectura</dcterms:isPartOf><dc:format>text/html</dc:format> <dc:description xml:lang="en"><![CDATA[ A white, amorphous mineral composed of silicate, carbonate, and calcium sulfate. It is often formed by the reaction of sulfates and concrete or mortar. Thaumasite crystal formation induces sulfate decay in the cement paste matrix. Conservation interventions seek to remove thaumasite or limit its attack. ]]></dc:description></metadata>