<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">Libyan desert glass</topic></authority><related type="broader"><topic>glass by composition or origin</topic></related><variant type="other"><topic>glass, Libyan desert</topic></variant> <note xml:lang="en"><![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. ]]></note></mads>