<?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">phosphorite</topic></authority><related type="other"><topic>apatite</topic></related><related type="broader"><topic>sedimentary rock by composition</topic></related><variant type="other"><topic>rock phosphate</topic></variant> <note xml:lang="en"><![CDATA[ Formerly, the term referred to a non-crystalline or fibrous form of apatite. In current usage, it is a general term referring to any sedimentary rock containing a high proportion of calcium phosphate. ]]></note></mads>