Cubic Zirconium is an artificial material, zirconia ZrO2, crystallized in cubic syngony. Widely used in jewelry as a synthetic imitation of precious stones.

The refractive index (2.15-2.25), that is, is close to diamond (2.417-2.419), so it is difficult to distinguish cubic zirconia from diamond by eye.

Shine like a diamond.

Hardness 7.5-8.5