<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31344725</termId><termName>cubic zirconia</termName><termType>PT</termType><termNote><![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. ]]></termNote><termCreatedDate>2026-03-30 20:32:58</termCreatedDate><relation><relationType>BT</relationType><termId>31320469</termId><termName>mineral</termName><termType>PT</termType></relation><relation><relationType>BT</relationType><termId>31376754</termId><termName>gemstones by specific type</termName><termType>PT</termType></relation></term>  </Zthes>