Rock Identifier
Turquoise (Hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O) — mineral
mineral

Turquoise

Hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

AI-generated identification · may be incorrect

Typically blue to blue-green with a waxy or subvitreous luster; Mohs hardness 5–6, cryptocrystalline/triclinic, usually opaque and lacking visible cleavage. The irregular specimen appears natural or lightly polished, though image identification is not definitive.

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Physical properties

Typically blue to blue-green with a waxy or subvitreous luster; Mohs hardness 5–6, cryptocrystalline/triclinic, usually opaque and lacking visible cleavage. The irregular specimen appears natural or lightly polished, though image identification is not definitive.

Formation & geological history

Forms as a secondary mineral in arid, copper-rich, weathered rocks, often replacing alumino-phosphate minerals. Deposits commonly formed during Cenozoic weathering, with famous sources in Iran, the southwestern United States, China, and Mexico.

Uses & applications

Used as a cabochon gemstone, beads, inlay, and carved ornament; lower-grade material is used decoratively. It has little industrial use because of softness and limited abundance.

Geological facts

Matrix veining may contain brown limonite or black manganese oxides; color can fade or discolor with chemicals, heat, or prolonged moisture. Imitations include dyed howlite, magnesite, and synthetic turquoise.

Field identification & locations

Identify by its opaque blue-green color, waxy surface, moderate softness, and possible matrix; it should not readily scratch glass. Common locations include Arizona, Nevada, New Mexico, Iran, Xinjiang, and Sonora.