<?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">silica</topic></authority><related type="narrower"><topic>organically modified silica</topic></related><related type="broader"><topic>inorganic material</topic></related><variant type="other"><topic>dioxide, silicon</topic></variant><variant type="other"><topic>silicon dioxide</topic></variant> <note xml:lang="en"><![CDATA[ The dioxide form of silicon, SiO2, occurring in quartz sand, flint, and agate. It is used chiefly in its prepared white powder form in the manufacture of glass, ceramics, and abrasives. ]]></note></mads>