<?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">lead glass</topic></authority><related type="narrower"><topic>flint glass</topic></related><related type="narrower"><topic>crystal</topic></related><related type="other"><topic>nonlead glass</topic></related><related type="broader"><topic>glass by composition or origin</topic></related><variant type="other"><topic>silicate glass, lead</topic></variant><variant type="other"><topic>glass, lead</topic></variant><variant type="other"><topic>glass, lead silicate</topic></variant><variant type="other"><topic>glass, lead-alkali</topic></variant><variant type="other"><topic>glass-of-lead</topic></variant><variant type="other"><topic>lead silicate glass</topic></variant><variant type="other"><topic>lead-alkali glass</topic></variant> <note xml:lang="en"><![CDATA[ Glass containing a high proportion of lead oxide and having a relatively high refractive index, with poor acid resistance and low rigidity; used in many optical components, neon-sign tubing, and light bulbs. ]]></note></mads>