mineral

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 subvitreous luster, Mohs hardness 5–6, cryptocrystalline structure, and no obvious cleavage; brown matrix is limonite or host rock. The polished, irregular pebble appears consistent with turquoise, though dyeing or stabilization cannot be excluded visually.

Identified September 12, 2026More mineral →

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Physical properties

Formation & geological history

Forms as a secondary mineral in arid, copper-rich, aluminum- and phosphate-bearing rocks through groundwater alteration, commonly from Cenozoic to older deposits. Major sources include Iran, the southwestern United States, Mexico, China, Chile, and Egypt.

Uses & applications

Used for cabochons, beads, inlay, carvings, and ornamental objects; historically important in jewelry and religious art. Softer or porous material is often stabilized with resin for durability.

Geological facts

Its blue color comes mainly from copper, while greener tones may reflect iron or dehydration. Matrix patterns and color vary strongly by mine and are not definitive proof of origin.

Field identification & locations

Identify by opaque blue-green color, waxy polish, low-to-moderate hardness, and brown matrix; glassy hardness or bubbles suggest imitation. Avoid acids, heat, and prolonged soaking, which can damage treated turquoise.