mineral

Turquoise

Turquoise, CuAl6(PO4)4(OH)8·4H2O

Hardness: 5.0 to 6.0; Color: Sky blue, bluish-green, to apple green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen in massive specimens); Specific Gravity: 2.6 to 2.9

Hardness: 5
Color: Sky blue, bluish-green, to apple green
Luster: Waxy to subvitreous

Identified June 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed as a secondary mineral by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals. Typically found in arid regions within volcanic rocks or weathered hydrothermal deposits.

Uses & applications

Primarily used as a gemstone for jewelry, carvings, and ornamental inlay. It has historically been prized for its unique color in various cultures including Egyptian, Aztec, and Native American.

Geological facts

Turquoise is one of the oldest gemstones known to man. Its name comes from the French 'pierre turquoise', meaning 'Turkish stone', because it first reached Europe via Turkey from mines in the historical Khorasan Province of Persia.

Field identification & locations

Identify by its sky blue to green color, waxy luster, and association with limonite or sandstone host rock (matrix). Commonly found in the Southwestern US (Arizona, Nevada), Iran, China, and Egypt. Collectors look for intense color and unique matrix patterns.