mineral

Turquoise

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

AI-generated identification · may be incorrect

Hardness (Mohs scale): 5-6; Color: Sky blue to blue-green; Luster: Waxy to sub-vitreous; Crystal system: Triclinic (usually massive or microcrystalline); Specific gravity: 2.6 - 2.9

Color: Sky blue to blue-green
Luster: Waxy to sub-vitreous

Identified March 29, 2026More mineral →

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Physical properties

Hardness (Mohs scale): 5-6; Color: Sky blue to blue-green; Luster: Waxy to sub-vitreous; Crystal system: Triclinic (usually massive or microcrystalline); Specific gravity: 2.6 - 2.9

Formation & geological history

Formed as a secondary mineral by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals (supergene processes). Found typically in arid climates within volcanic rocks or sedimentary environments rich in aluminum and phosphorus.

Uses & applications

Primarily used as an ornamental gemstone for jewelry, beads, and cabochons. It is also a popular collector's mineral and holds significant cultural value in Native American and Middle Eastern art.

Geological facts

Turquoise is one of the oldest gemstones in human history, used by the Ancient Egyptians as early as 3000 BCE. Its name comes from the French 'turquois' meaning 'Turkish', as it was first brought to Europe through Turkey from mines in Persia.

Field identification & locations

Identify in the field by its distinct robin-egg blue color and waxy luster. It often contains a 'matrix' of brown limonite or black manganese oxide. Common locations include the Southwestern USA (Arizona, Nevada), Iran, and China.