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 blue-green, Luster: Waxy to sub-vitreous, Crystal structure: Triclinic (usually cryptocrystalline/massive), Cleavage: Perfect (rarely seen in massive form), Specific gravity: 2.6-2.9.

Identified March 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed by the percolation of acidic aqueous solutions through pre-existing minerals containing copper, aluminum, and phosphorus. It is a secondary mineral usually found in arid regions within weathered volcanic or sedimentary rocks near copper deposits.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons, beads, and inlay) and decorative ornaments. It is also an important cultural mineral for indigenous peoples of the American Southwest and Middle East.

Geological facts

Turquoise is one of the oldest gemstones in 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 from Persian mines.

Field identification & locations

Identify in the field by its distinct robin's egg blue color and waxy appearance. Often found in nodules or vein fillings. It is frequently associated with limonite (brown matrix) and quartz. Significant deposits are found in Iran, Arizona, New Mexico, and China.