<?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">chert</topic></authority><related type="narrower"><topic>flint</topic></related><related type="narrower"><topic>jasper</topic></related><related type="broader"><topic>sedimentary rock by composition</topic></related><related type="broader"><topic>mineral</topic></related><related type="broader"><topic>quartz</topic></related><variant type="other"><topic>cherts</topic></variant> <note xml:lang="en"><![CDATA[ Fine-grained, dense sedimentary rock consisting of interlocking crystals of quartz approximately 30 microns in diameter. Chert and its varieties, such as flint, are non-gem varieties of cryptocrystalline-granular quartz. These stones chip very easily and thus may be fashioned into tools with a sharp edge; they are also used for building. ]]></note></mads>