Turquoise

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

Rock Type: mineral

Turquoise

Physical Properties

Hardness: 5.0–6.0 (Mohs); Color: Sky-blue to greenish-blue; Luster: Waxy to sub-vitreous; Crystal Structure: Triclinic; Cleavage: Perfect; Specific Gravity: 2.6–2.9

Formation & Geological History

Formed through the infiltration of meteoric acidic solutions during the weathering and oxidation of pre-existing minerals. It is a secondary mineral usually found in volcanic rocks or arid environments.

Uses & Applications

Predominantly used as a gemstone in jewelry (cabochons, beads, and inlay) and for ornamental decorative objects. Highly valued in traditional Southwestern and Middle Eastern artistry.

Geological Facts

Persians called it 'píruzeh' (victory) and the name Turquoise comes from the French 'turquois' (Turkish), as it was originally brought to Europe from Iranian mines through Turkey.

Field Identification & Locations

Identify by its waxy luster, sky-blue 'Robin's Egg' color, and lack of transparency. Common locations include Iran, Arizona (USA), Nevada (USA), and China.

Identified on: 4/18/2026

Mode: Standard