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

Turquoise cabochon

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

AI-generated identification · may be incorrect

Opaque blue-green, polished, with dark brown-black matrix veining; waxy to subvitreous luster, microcrystalline/triclinic structure, no obvious cleavage, Mohs hardness 5–6, specific gravity about 2.6–2.8.

Identified More mineral
Explore Turquoise cabochon in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Opaque blue-green, polished, with dark brown-black matrix veining; waxy to subvitreous luster, microcrystalline/triclinic structure, no obvious cleavage, Mohs hardness 5–6, specific gravity about 2.6–2.8.

Formation & geological history

Forms as a secondary mineral in arid, oxidized copper deposits when phosphate-rich groundwater alters aluminum-bearing rocks. Most deposits are Cenozoic to Mesozoic in age, though turquoise occurrences span many geological periods.

Uses & applications

Used primarily for cabochons, beads, inlay, and ornamental objects; lower-grade material is stabilized or reconstructed for jewelry. Fine natural turquoise is collectible, while matrix patterns strongly influence desirability.

Geological facts

The blue color comes mainly from copper; greener tones commonly reflect iron substitution or weathering. The specimen appears to be matrix-bearing turquoise, possibly from a commercial source.

Field identification & locations

Identify by its opaque blue-green color, low-to-moderate hardness, light weight, and irregular matrix; beware dyed howlite or magnesite imitations. Common sources include Iran, southwestern United States, China, Mexico, Chile, and Egypt.