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

Cubic Zirconia (Simulated Diamond)

Zirconium Dioxide (ZrO2)

Hardness: 8.0-8.5 Mohs scale; Color: Colorless (clear); Luster: Adamantine (diamond-like); Crystal structure: Cubic (isometric system); Cleavage: None; Specific Gravity: 5.6-6.0 (heavier than diamond).

Hardness
8
Color
Colorless (clear)
Luster
Adamantine (diamond-like)
Identified More mineral (synthetic)

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Physical properties

Hardness: 8.0-8.5 Mohs scale; Color: Colorless (clear); Luster: Adamantine (diamond-like); Crystal structure: Cubic (isometric system); Cleavage: None; Specific Gravity: 5.6-6.0 (heavier than diamond).

Formation & geological history

Formed through a lab-grown process such as the 'skull melt' method. While zirconium dioxide occurs naturally as the rare mineral Baddeleyite (monoclinic), the cubic form is almost exclusively synthetic, created by heating zirconium oxide powder with stabilizers like yttrium or calcium to over 2700°C.

Uses & applications

Primary use is in the jewelry industry as a diamond simulant due to its high dispersion and low cost. Also used in industrial applications for thermal barriers, dental crowns, and oxygen sensors.

Geological facts

Mass production began in 1976 by Soviet scientists. It is visually similar to diamond but has 1.7 times the density, meaning a cubic zirconia will be significantly heavier than a diamond of the same physical size.

Field identification & locations

Identify in the field by checking for excessive fire (rainbow flashes) more intense than diamond, lack of inclusions under magnification, and rounded facet edges over time. In common settings, it's often found in silver-toned metals with hallmark stamps like 'CZ' or '925'.