gemstone

Polished turquoise

Turquoise (hydrated copper–aluminum phosphate; CuAl₆(PO₄)₄(OH)₈·4H₂O), likely with brown limonite matrix

AI-generated identification · may be incorrect

Opaque, blue-green to green with dark brown/black matrix veining; waxy to dull luster and typically cryptocrystalline structure. Mohs hardness is 5–6; no prominent cleavage; specific gravity about 2.6–2.9. The rounded, glossy surface indicates tumbling or polishing.

Identified September 20, 2026More gemstone →

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At a glance

Common name: Polished turquoise
Scientific name: Turquoise (hydrated copper–aluminum phosphate; CuAl₆(PO₄)₄(OH)₈·4H₂O), likely with brown limonite matrix
Category: gemstone
Identified: September 20, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a common small polished piece; $30–$150+ for attractive natural, well-colored material with desirable matrix. Treatment, provenance, and durability strongly affect value.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Forms as a secondary phosphate mineral in arid, oxidized zones of copper deposits, commonly replacing aluminum-rich rock. Most deposits are Cenozoic to older, with major sources in Iran, the southwestern United States, China, Chile, and Mexico.

Uses & applications

Used for cabochons, beads, carvings, and ornamental objects; historically important in jewelry and ceremonial art. It has limited industrial use.

Geological facts

Color depends on copper, iron, and water content: iron commonly shifts turquoise toward green. Brown matrix is usually iron oxide minerals such as limonite, though host-rock patterns can vary.

Field identification & locations

Identify by its opaque blue-green color, low-to-moderate hardness, waxy polish, and copper response; a streak, hardness, or chemical test should be done inconspicuously because dyed imitations and stabilized turquoise are common. Similar-looking chrysocolla, variscite, and dyed howlite are alternatives.