<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31373651</termId><termName>sodium sulfate</termName><termType>PT</termType><termNote><![CDATA[ A sodium compound which in its anhydrous form occurs in nature as a chemical precipitate found in the minerals thenardite and mirabilite. It may also be obtained synthetically by mixing sodium chloride and sulfuric acid. As a solid or powder, sodium sulphate is used in the manufacture of various products. In conservation science it is addressed as an agent of salt damage to stone. ]]></termNote><termCreatedDate>2026-03-30 20:40:46</termCreatedDate><relation><relationType>UF</relationType><termId>31373652</termId><termName>sodium sulphate</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31373653</termId><termName>sulfate, sodium</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31343447</termId><termName>sodium compounds</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31344683</termId><termName>mirabilite</termName><termType>PT</termType></relation></term>  </Zthes>