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 Structure: Triclinic (usually massive); Specific Gravity: 2.6-2.9

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

Identified July 11, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals; typically found in arid regions within volcanic rocks or sedimentary phosphate deposits.

Uses & applications

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

Geological facts

Turquoise is one of the oldest known gemstones, used by Ancient Egyptians and Native Americans for over 3,000 years. Its name comes from the French 'turquois' meaning Turkish, as it first reached Europe via Turkey.

Field identification & locations

Identified by its distinctive blue-green hue and waxy luster. Common in the Southwestern US (Arizona, Nevada) and Iran. Watch for 'Howlite' dyed to look like turquoise; real turquoise is harder and color does not rub off with acetone.