Turquoise (Rough)

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

Rock Type: mineral

Turquoise (Rough)

Physical Properties

Hardness: 5-6 (Mohs scale), Color: Sky-blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually massive), Cleavage: Perfect (rarely seen in massive forms), Specific Gravity: 2.6-2.9

Formation & Geological History

Formed as a secondary mineral by the percolation of meteoric water through weathered volcanic or sedimentary rocks rich in aluminum and phosphorus, typically in arid regions containing copper deposits.

Uses & Applications

Primarily used as a gemstone for jewelry, ornamental carvings, and used extensively in Native American crafts.

Geological Facts

Turquoise is one of the oldest known gemstones, used by the Ancient Egyptians as early as 3000 BCE. Its name comes from the French 'turquois', meaning 'Turkish', as it first reached Europe via Turkey from Persian mines.

Field Identification & Locations

Identify in the field by its distinct robin-egg blue to greenish-blue color and waxy appearance; it often occurs as veins or crusts in host rocks like limonite or rhyolite. Commonly found in the Southwestern US, Iran, China, and Egypt.

Identified on: 4/15/2026

Mode: Standard