mineral

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminum)

AI-generated identification · may be incorrect

Hardness: 5-6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually massive); Specific gravity: 2.6-2.9.

Hardness: 5-6 (Mohs)
Color: Sky blue to blue-green
Luster: Waxy to subvitreous

Identified July 3, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually massive); Specific gravity: 2.6-2.9.

Formation & geological history

Turquoise is a secondary mineral formed by the percolation of meteoric water through aluminous rock in the presence of copper minerals, usually in arid or desert climates.

Uses & applications

Primarily used as a gemstone for jewelry (beads, cabochons, and inlays) and for ornamental carvings.

Geological facts

It is one of the oldest gemstones used in human history, dating back to ancient Egypt (c. 3000 BCE). It is porous and can change color if exposed to oils, perspiration, or light.

Field identification & locations

Identify by its waxy luster and characteristic color. It is often found in Nevada, Arizona, New Mexico, Iran, and China. Collectors should watch for 'stabilized' or dyed howlite imitations.