mineral

Turquoise

Hydrate 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 blue-green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

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

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs scale); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

Formation & geological history

A secondary mineral formed by the action of percolating acidic solutions during the weathering and oxidation of pre-existing minerals. Usually found in arid climates within volcanic rocks or phosphorus-rich sedimentary rocks.

Uses & applications

Primarily used in jewelry making (cabochons, beads, inlays) and as an ornamental stone. It has significant value for gemstone collectors and in Native American cultural crafts.

Geological facts

Turquoise is one of the oldest gemstones in human history; it was mined by Ancient Egyptians as early as 3000 BCE. Its name comes from the French 'turquois', meaning 'Turkish', as it first reached Europe via Turkey.

Field identification & locations

Identify by its unique 'robin\'s egg' blue color and often presence of a 'matrix' (veins of host rock like limonite or sandstone). Commonly found in Iran, Southwestern USA, China, and Mexico.