<?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">petrographic microscopes</topic></authority><related type="broader"><topic>microscopes</topic></related><variant type="other"><topic>microscope, petrographic</topic></variant><variant type="other"><topic>microscopes, petrographic</topic></variant><variant type="other"><topic>petrographic microscope</topic></variant><variant type="other"><topic>petrological microscopes</topic></variant> <note xml:lang="en"><![CDATA[ Microscopes that employ polarized light that vibrates in a single plane so that light can be transmitted through the specimen. It is used to examine thin sections of rocks  and minerals. ]]></note></mads>