gemstone

Cubic Zirconia (CZ)

Cubic Zirconium Dioxide (ZrO2)

Hardness: 8-8.5 Mohs scale. Color: Colorless (in this specimen). Luster: Adamantine. Crystal Structure: Cubic. Specific Gravity: 5.6-6.0. High dispersion (fire) and brilliance.

Hardness: 8-8
Color: Colorless (in this specimen)
Luster: Adamantine

Identified July 6, 2026More gemstone →

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Physical properties

Hardness: 8-8.5 Mohs scale. Color: Colorless (in this specimen). Luster: Adamantine. Crystal Structure: Cubic. Specific Gravity: 5.6-6.0. High dispersion (fire) and brilliance.

Formation & geological history

Primarily lab-grown for jewelry. Natural baddeleyite exists but cubic crystals are extremely rare in nature; most CZ is synthesized using the skull melt process where the material is heated to 2,750°C.

Uses & applications

Widely used as a low-cost diamond simulant in jewelry, and in industrial applications such as dental crowns and thermal barrier coatings.

Geological facts

Cubic Zirconia is optically flawless and heavier than diamond of the same size. It was first successfully grown in a laboratory in the 1970s and remains the most popular diamond competitor.

Field identification & locations

Identify by its weight (denser than diamond) and its tendency to show more colorful 'fire' flashes under light. Unlike diamonds, it is a thermal insulator and will not pass a standard diamond tester.