mineral

Tumbled turquoise

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

AI-generated identification · may be incorrect

Opaque bright blue to blue-green, commonly with brown or gray matrix; waxy to subvitreous luster and microcrystalline/triclinic structure. Mohs hardness 5–6, poor cleavage, specific gravity about 2.6–2.8; this specimen appears polished or tumbled.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms as a secondary mineral in arid, oxidized copper deposits when phosphate-bearing groundwater alters aluminum-rich rock. Most deposits are Cenozoic to relatively young geologically, though turquoise occurs in older host rocks as well.

Uses & applications

Used as a cabochon gemstone, beads, carvings, inlay, and decorative objects; lower-grade material is also stabilized or reconstituted for jewelry.

Geological facts

Color comes chiefly from copper, while iron commonly shifts it toward green. Veining is host-rock matrix, and vivid blue material from historic Southwestern U.S. mines is especially prized.

Field identification & locations

Identify it by its intense blue-green color, low-to-moderate hardness, opaque waxy surface, and occasional matrix; beware dyed howlite or magnesite imitations. Common sources include Iran, Arizona, Nevada, China, Mexico, and Chile.