mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
AI-generated identification · may be incorrectHardness: 5-6 (Mohs scale), Color: Sky blue to apple green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), Cleavage: None/Perfect (rarely seen), Specific gravity: 2.6-2.9.
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Physical properties
Hardness: 5-6 (Mohs scale), Color: Sky blue to apple green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), Cleavage: None/Perfect (rarely seen), Specific gravity: 2.6-2.9.
Formation & geological history
Secondary mineral formed by the action of percolating acidic solutions during the weathering and oxidation of pre-existing minerals. Typically found in arid regions in veins or pipes traversing altered igneous rocks.
Uses & applications
Predominantly used as a gemstone in jewelry (beads, cabochons, carvings) and for ornamental purposes. It has significant cultural use in Native American and Middle Eastern crafts.
Geological facts
Turquoise is one of the oldest known gemstones, used by Ancient Egyptians as early as 3000 BCE. Its name comes from the French 'turquois' meaning 'Turkish', as it was historically brought to Europe through Turkey.
Field identification & locations
Identify by its distinctive blue-green color, lack of transparency (opaque), and characteristic brown or black matrix veins. In the field, look for it in arid climates near copper deposits. Commonly found in Southwestern USA, Iran, and China.
