<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31375037</termId><termName>Libyan desert glass</termName><termType>PT</termType><termNote><![CDATA[ A naturally occurring yellow or greenish glass made of silica found in parts of the Libyan Desert, the Western Desert of west Egypt, and along the Libyan-Egyptian border. Its origins remain a debated issue within the scientific community, but may be the result of a meteor impact fusing desert sand. The glass was used as a gemstone by the ancient Egyptians, and also as a material for paleolithic tools. ]]></termNote><termCreatedDate>2026-03-30 20:41:08</termCreatedDate><relation><relationType>UF</relationType><termId>31375038</termId><termName>glass, Libyan desert</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31344443</termId><termName>glass by composition or origin</termName><termType>PT</termType></relation></term>  </Zthes>