mineral

Turquoise

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

AI-generated identification · may be incorrect

Hardness: 5-6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually massive); Specific gravity: 2.6-2.9.

Hardness: 5-6 (Mohs)
Color: Sky blue to blue-green
Luster: Waxy to subvitreous

Identified July 20, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually massive); Specific gravity: 2.6-2.9.

Formation & geological history

Turquoise is a secondary mineral formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals. It is commonly found in arid climates within volcanic or sedimentary host rocks.

Uses & applications

Primarily used as a gemstone for jewelry (beads, cabochons) and ornamental carvings. It has been used as a decorative stone for thousands of years.

Geological facts

It is one of the oldest known gemstones, used by the ancient Egyptians, Aztecs, and Persians. Turquoise is the traditional birthstone for December.

Field identification & locations

Identify by its unique 'robin's egg blue' color and dark, web-like matrix (veins of host rock). In the field, look for it in arid regions near copper deposits. Much modern turquoise is stabilized or dyed.