mineral

Turquoise

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

AI-generated identification · may be incorrect

Opaque blue-green, waxy to subvitreous luster, Mohs hardness 5–6, cryptocrystalline structure, no prominent cleavage, and specific gravity about 2.6–2.9. The dark web-like matrix likely consists of iron or manganese oxides and host rock.

Identified September 18, 2026More mineral →

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Physical properties

Formation & geological history

Forms as a secondary mineral in arid, oxidized zones of copper deposits, typically replacing aluminum- and phosphate-bearing rock. Deposits range from young weathering zones to geologically ancient hydrothermal systems.

Uses & applications

Used as a cabochon gemstone, inlay, beads, and carvings; historically important in jewelry and ornament. It has little industrial use beyond decorative applications.

Geological facts

Its blue color comes mainly from copper, while greener tones reflect iron substitution or alteration. Common imitations include dyed howlite and magnesite.

Field identification & locations

Identify by its opaque blue color, waxy surface, natural matrix, moderate softness, and inability to scratch glass reliably. Major sources include Arizona, Nevada, Iran, China, Mexico, and Chile; avoid acids, heat, and harsh chemicals.