mineral

Turquoise

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

Hardness: 5-6 (Mohs scale), Color: Sky-blue to apple-green, Luster: Waxy to sub-vitreous, Crystal Structure: Triclinic (rarely found in crystals), Cleavage: Perfect, Specific Gravity: 2.6-2.9

Identified May 24, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs scale), Color: Sky-blue to apple-green, Luster: Waxy to sub-vitreous, Crystal Structure: Triclinic (rarely found in crystals), Cleavage: Perfect, 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; usually found in arid regions within volcanic rocks or sedimentary environments rich in aluminum and phosphorus.

Uses & applications

Predominantly used as a gemstone for jewelry, ornamental carvings, and architectural inlay. It is also a highly prized collector's mineral.

Geological facts

Turquoise is one of the oldest gemstones in human history, used by the Ancient Egyptians since at least 3000 BCE. The name is derived from the Old French 'turquoise', meaning 'Turkish', as the stones originally reached Europe via Turkey.

Field identification & locations

Identify in the field by its distinctive blue-green color, lack of transparency, and association with copper deposits in arid climates. Look for 'matrix' (vein patterns of host rock). Major deposits are in Iran, Southwest USA, China, and Egypt.

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