Synthetic cubic zirconia (or CZ), is the cubic crystalline form of zirconium dioxide (ZrO₂). The synthesized material is hard, optically flawless and usually colourless, but is also be made in a variety of different colours. It should not be confused with zircon, which is a zirconium silicate (ZrSiO₄).
00000Because of its low cost, durability, and close visual likeness to diamond, synthetic cubic zirconia has remained the most gemologically and economically important competitor for diamonds since 1976. Its main competition as a synthetic gemstone is the more recently cultivated material, synthetic moissanite.