mineral

Turquoise

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

AI-generated identification · may be incorrect

Opaque blue-green, typically waxy to dull luster; Mohs hardness 5–6; triclinic phosphate mineral with no prominent cleavage and conchoidal to uneven fracture. The vivid cyan color and possible dark matrix are characteristic, though this piece appears polished or tumbled.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Forms as a secondary mineral in arid-region copper deposits when phosphate-rich groundwater alters aluminum-bearing rocks; most deposits are Cenozoic to older, commonly associated with weathered porphyry copper systems.

Uses & applications

Used as a gemstone, beads, cabochons, carvings, and ornamental objects; historically important in jewelry and decorative arts. Stabilized or dyed turquoise is common commercially.

Geological facts

Its color results mainly from copper, while iron can shift it toward green and zinc may create pale blue varieties. It commonly occurs with limonite, chrysocolla, quartz, and host-rock matrix.

Field identification & locations

Common localities include Iran, the southwestern United States, Mexico, China, Chile, and Egypt. Field identification relies on opaque blue-green color, relatively low hardness, porous/waxy texture, and reaction to a hot needle or solvent only with caution; avoid destructive tests.