mineral

Tumbled turquoise

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

AI-generated identification · may be incorrect

Typically blue to blue-green with a waxy to dull luster; Mohs hardness 5–6, cryptocrystalline structure, no obvious cleavage, and specific gravity about 2.6–2.9. The dark patches may be iron/manganese matrix or surface inclusions.

Identified August 16, 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 turquoise is Cenozoic to younger, though deposits can occur in much older host rocks.

Uses & applications

Used for cabochons, beads, carvings, and ornamental objects; historically important in jewelry and decorative arts. It has little industrial use beyond lapidary applications.

Geological facts

Natural turquoise is porous and may be stabilized with resin; dyed howlite or magnesite are common imitations. Color generally ranges from robin’s-egg blue to green depending on copper, iron, and water content.

Field identification & locations

Common sources include Arizona, Nevada, New Mexico, Iran, China, and Tibet. Identify it by its opaque blue-green color, relatively low hardness, waxy surface, and possible brown/black matrix; laboratory testing is needed to distinguish treated material.