Rock Identifier
Cubic Zirconia (CZ) (Cubic Zirconium Dioxide (ZrO2)) — mineral (synthetic)
mineral (synthetic)

Cubic Zirconia (CZ)

Cubic Zirconium Dioxide (ZrO2)

Hardness: 8.0-8.5 Mohs; Color: Colorless (typically), but can be varied with dopants; Luster: Adamantine; Crystal Structure: Isometric/Cubic; Cleavage: None (conchoidal fracture); Specific Gravity: 5.6-6.0.

Hardness
8
Color
Colorless (typically), but can be varied with dopants
Luster
Adamantine
Identified More mineral (synthetic)

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Physical properties

Hardness: 8.0-8.5 Mohs; Color: Colorless (typically), but can be varied with dopants; Luster: Adamantine; Crystal Structure: Isometric/Cubic; Cleavage: None (conchoidal fracture); Specific Gravity: 5.6-6.0.

Formation & geological history

Laboratory-created via a skull melting process. While baddeleyite (monoclinic ZrO2) occurs naturally as a rare mineral, the cubic form shown here is synthesized at temperatures around 2,750°C using stabilizers like yttrium or calcium oxide.

Uses & applications

Primarily used in jewelry as a diamond stimulant due to its low cost and high dispersion. Also used in industry for laser components, optical lenses, and high-temperature ceramics.

Geological facts

First synthesized in the late 19th century, but commercial production only took off in the 1970s. It is much heavier than diamond and has a higher rate of dispersion, causing it to produce more 'fire' (colorful flashes) than a real diamond.

Field identification & locations

In the field of gemology, it is identified by its high specific gravity (it will feel heavier than a diamond of the same size), lack of inclusions under magnification, and its tendency to become 'cloudy' or scratched over time unlike diamond. If set in silver (often marked 925), it is almost certainly CZ.