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 massive or cryptocrystalline), Specific gravity: 2.6 - 2.9

Identified March 25, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to sub-vitreous, Crystal structure: Triclinic (usually massive or cryptocrystalline), 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; commonly found in arid climates within volcanic or sedimentary host rocks.

Uses & applications

Primarily used as a gemstone for jewelry and ornamental carvings. Historically significant in Native American and Persian cultures for spiritual and decorative purposes.

Geological facts

Turquoise is one of the oldest known gemstones, used by Ancient Egyptians since at least 3000 BCE. Its color comes from copper (blue) or iron (green substitute for aluminum).

Field identification & locations

Identify by its characteristic robin's egg blue color and waxy texture; it often contains 'matrix' (veins of host rock). Commonly found in Iran, Southwestern United States, China, and Egypt. Collectors look for 'Sleeping Beauty' blue colors without excessive matrix.