mineral

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Hardness: 5-6 Mohs. Color: Sky-blue to green. Luster: Waxy to sub-vitreous. Crystal system: Triclinic (usually massive). Cleavage: None visible in massive form. Specific Gravity: 2.6 to 2.9.

Hardness: 5-6 Mohs
Color: Sky-blue to green
Luster: Waxy to sub-vitreous

Identified July 1, 2026More mineral →

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Physical properties

Hardness: 5-6 Mohs. Color: Sky-blue to green. Luster: Waxy to sub-vitreous. Crystal system: Triclinic (usually massive). Cleavage: None visible in massive form. Specific Gravity: 2.6 to 2.9.

Formation & geological history

Formed by the percolation of meteoric waters through weathered aluminum-rich igneous or sedimentary rocks in arid environments, carrying copper and phosphorus which precipitate in veins and nodules.

Uses & applications

Primarily used as a gemstone in jewelry, inlay material, and for ornamental carvings. Minor historical use as a pigment.

Geological facts

One of the oldest gemstones in human history, it was mined by Ancient Egyptians as early as 3000 BCE. Its name comes from the Old French word for 'Turkish' because it reached Europe through Turkey.

Field identification & locations

Identify by its blue-to-green hue, waxy luster, and association with copper deposits in desert regions like the American Southwest, Iran, or China. Collectors should look for 'matrix' (host rock inclusions) which often appear as dark veins.