<?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">cubic zirconia</topic></authority><related type="broader"><topic>mineral</topic></related><related type="broader"><topic>gemstones by specific type</topic></related> <note xml:lang="en"><![CDATA[ The cubic crystalline form of zirconium dioxide (ZrO2). As a synthetic gem it is often used as an inexpensive replacement for a diamond. Color most often ranges from white to light yellow and brown, but as a synthetic, can be produced in a large variety of colors. Its refractive index and colour dispersion are fairly close to the diamond, but its hardness is lower and its specific gravity much higher. ]]></note></mads>