mineral

Turquoise

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

AI-generated identification · may be incorrect

Hardness: 5-6 (Mohs scale); Color: Sky blue to apple green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen); Specific Gravity: 2.6-2.9.

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

Identified March 22, 2026More mineral →

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Physical properties

Formation & geological history

A secondary mineral formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals (often in copper deposits) in arid, volcanic environments.

Uses & applications

Primarily used as a gemstone for jewelry and ornamental purposes; also significant in cultural and spiritual artifacts.

Geological facts

Turquoise has been mined since at least 3000 BCE in Ancient Egypt. It is one of the few minerals that gives its name to a color. It often contains dark vein-like inclusions called 'matrix,' which are remnants of the host rock.

Field identification & locations

Identify in the field by its distinct robin's egg blue or green color and its occurrence in arid regions embedded in host rocks like limonite or sandstone. Found commonly in Iran, USA (Arizona/Nevada), and China.