mineral

Turquoise

Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O

AI-generated identification · may be incorrect

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

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

Identified May 9, 2026More mineral →

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Physical properties

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

Formation & geological history

Secondary mineral formed in the alteration zone of copper deposits through the percolation of acidic aqueous solutions through aluminous rocks in arid regions.

Uses & applications

Primarily used as a gemstone in jewelry, decorative carvings, and as a popular collector's item in the Southwest United States and Middle East.

Geological facts

One of the oldest known gemstones, used by the Ancient Egyptians and Persians. The name comes from 'turquois', the French word for Turkish, because it was first brought to Europe through Turkey.

Field identification & locations

Identify by its unique sky-blue to green color and dark 'spiderweb' matrix of host rock. Commonly found in the American Southwest (Arizona, Nevada) and Iran. Watch for dyed imitations like howlite.