mineral

Turquoise

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

AI-generated identification · may be incorrect

Hardness: 5-6 Mohs. Color: Sky-blue to apple-green. Luster: Waxy to subvitreous. Crystal structure: Triclinic (usually occurs as massive/cryptocrystalline). Specific gravity: 2.6-2.9.

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

Identified June 27, 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 occurs as massive/cryptocrystalline). 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. Often found in arid regions within volcanic rocks or sedimentary phosphate-bearing rocks.

Uses & applications

Primarily used as a gemstone in jewelry, decorative carvings, and as a highly sought-after collector mineral.

Geological facts

Turquoise is one of the oldest known gemstones, used by Ancient Egyptians and Persians for over 5,000 years. The word 'turquoise' comes from the French for 'Turkish', as it first reached Europe via Turkey from Persian mines.

Field identification & locations

Identify in the field by its distinct blue-green color, lack of transparency, and association with host rocks like Limonite. Common in the Southwestern US (Arizona, Nevada), Iran, and China.