Zirconium for use in jewelry. Zirconia is a component in some abrasives, such as grinding wheels and sandpaper. A small fraction of the zircon is converted to the metal, which finds various niche applications. Because of zirconium's excellent resistance to corrosion, it is often used as an alloying agent in materials that are exposed to aggressive environments, such as surgical appliances, light filaments, and watch cases. The high reactivity of zirconium with oxygen at high temperatures is exploited in some specialised applications such as explosive primers and as getters in vacuum tubes. The same property is (probably) the purpose of including
Cubic zirconia moissanite. Cubic zirconia is crystallographically isometric, an important attribute of a would-be diamond simulant. During synthesis zirconium oxide would naturally form monoclinic crystals, its stable form under normal atmospheric conditions. A stabilizer is required for cubic crystals to form, and remain stable at ordinary temperatures; this may be typically either yttrium or calcium oxide, the amount of stabilizer used depending on the many recipes of individual manufacturers. Therefore, the physical and optical properties of synthesized CZ vary, all values being ranges. It is a dense substance, with a specific gravity between 5.6 and 6.0 — at least 1.6 times that