<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31344641</termId><termName>plattnerite</termName><termType>PT</termType><termNote><![CDATA[ Naturally occurring mineral form of lead dioxide; black crystals or blackish brown masses. In mural paintings, lead-based pigments may convert to plattnerite over time, causing deterioration and blackening to the pictorial surface. ]]></termNote><termCreatedDate>2026-03-30 20:32:57</termCreatedDate><relation><relationType>BT</relationType><termId>31320469</termId><termName>mineral</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31320554</termId><termName>lead</termName><termType>PT</termType></relation></term>  </Zthes>