<?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">hydroxyapatite</topic></authority><related type="broader"><topic>calcium phosphate</topic></related><variant type="other"><topic>calcium hydroxyapatite</topic></variant><variant type="other"><topic>calcium phosphate hydroxide</topic></variant><variant type="other"><topic>hydroxylapatite</topic></variant> <note xml:lang="en"><![CDATA[ A complex calcium phosphate, a naturally occuring mineral form of calcium apatite,  that serves as an important component of tooth enamel and vertebrate bone. In an archaeological context,  hydroxyapatite from human and animal remains is studied to reconstruct ancient diet. ]]></note></mads>