mineral

Turquoise (likely Sleeping Beauty variety or treated Howlite imitation)

Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O

AI-generated identification · may be incorrect

Hardness: 5–6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), specific gravity: 2.6–2.9

Identified March 28, 2026More mineral →

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Physical properties

Hardness: 5–6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), specific gravity: 2.6–2.9

Formation & geological history

Formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals; typically found in arid regions in veins or crusts within volcanic or sedimentary rocks.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular gemstone for collectors.

Geological facts

Turquoise is one of the oldest gemstones used by humans, prized by the Ancient Egyptians and Persians. It is the birthstone for December. Its color is derived from copper (blue) and iron/chrome (green).

Field identification & locations

Identify in the field by its distinct robin-egg blue color and lack of transparency. Common locations include the Southwestern USA (Arizona, Nevada), Iran, and China. In jewelry like the 'Tree of Life' pendant shown, it is identified by its opaque blue chips.