<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31375367</termId><termName>cristobalite</termName><termType>PT</termType><termNote><![CDATA[ Along with quartz and tridymite, one of the three principal forms of silica. It is a high temperature form of quartz found naturally formed in volcanic rock.  ]]></termNote><termCreatedDate>2026-03-30 20:41:14</termCreatedDate><relation><relationType>BT</relationType><termId>31344506</termId><termName>quartz</termName><termType>PT</termType></relation></term>  </Zthes>