Cubic Zirconium
Cubic zirconium (or CZ) is based on zirconium oxide (ZrO2), a mineral that is extremely rare in nature but is widely synthesized. Generally, Cubic Zirconium is the name given to the family of monocrystals, created on the base of high temperature oxides. The synthesized material is hard, optically flawless and usually colorless, but may be made in a variety of different colors.

Because of its low cost, durability, and close visual likeness to diamond, synthetic cubic zirconium has been the most gemologically and economically important diamond simulation. It can be produced either transparent or opaque in nearly any color and can be faceted in many cuts. Its main competition as a synthetic gemstone is the more recently cultivated material moissanite.

Cubic zirconium is, as its name would imply, crystallographically isometric. Synthesized material contains a certain mole percentage (10-15%) of metal oxide stabilizer, typically Yttrium oxide. In colored CZ other oxides are added to produce the colors. The stabilizer is required for cubic structure formation; otherwise zirconium oxide would form monoclinic crystals during synthesis. The amount and the type of stabilizer used depend on the recipes of individual manufacturers. Therefore the physical and optical properties of synthesized CZ vary, all values being ranges