mineral

Turquoise

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O

AI-generated identification · may be incorrect

Blue-green, opaque, waxy to subvitreous luster; Mohs hardness 5–6; triclinic crystal system, usually massive or nodular with poor cleavage; specific gravity about 2.6–2.8. The specimen appears naturally rough or partially shaped, with brown matrix and surface scratches.

Identified August 25, 2026More mineral →

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Physical properties

Formation & geological history

A hydrated copper-aluminum phosphate formed by groundwater alteration in arid regions, commonly replacing aluminum-rich rocks. Most deposits are Cenozoic to relatively young geologically, though individual deposits vary in age.

Uses & applications

Used as a gemstone, cabochon, bead, carving material, and collector specimen; historically important in jewelry and ornamentation. It is too soft and porous for most heavy industrial or construction uses.

Geological facts

Its blue-green color comes mainly from copper, while iron commonly shifts it toward green and matrix produces brown webbing. Stabilized or reconstituted turquoise is common in commerce.

Field identification & locations

Identify by opaque blue-green color, low-to-moderate hardness, waxy luster, and copper staining; avoid confusing dyed howlite or magnesite. Major sources include Iran, southwestern United States, China, Mexico, Chile, and Egypt.