Rock Identifier
Polished turquoise cabochon (Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O) — gemstone
gemstone

Polished turquoise cabochon

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

AI-generated identification · may be incorrect

Opaque blue-green with brown/tan host-rock matrix and a polished, waxy-to-vitreous luster. Mohs hardness 5–6; triclinic crystal system, typically massive rather than visibly crystalline; the photo does not establish authenticity or treatments.

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Physical properties

Opaque blue-green with brown/tan host-rock matrix and a polished, waxy-to-vitreous luster. Mohs hardness 5–6; triclinic crystal system, typically massive rather than visibly crystalline; the photo does not establish authenticity or treatments.

Formation & geological history

Forms when copper-bearing fluids alter aluminum- and phosphate-rich rocks in arid-zone deposits, commonly as vein or nodular material. Deposits range from ancient to geologically recent; the specimen’s age and source cannot be determined from the image.

Uses & applications

Cut and polished for cabochons, beads, and decorative objects; also collected as a mineral specimen.

Geological facts

Turquoise’s characteristic blue-green color comes chiefly from copper; iron can contribute green tones, while brown veining is often host rock.

Field identification & locations

The blue-green color, opaque appearance, and natural-looking matrix are consistent with turquoise, but dyed howlite or other imitations can look similar. Major sources include Iran, the southwestern United States, China, and Mexico; a gemological test is needed to confirm identity and treatment.