mineral

Turquoise

Hydrous 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; Cleavage: None (conchoidal fracture); Specific gravity: 2.60–2.90

Hardness: 5-6 (Mohs scale)
Color: Sky blue to blue-green
Luster: Waxy to subvitreous

Identified April 3, 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; Cleavage: None (conchoidal fracture); Specific gravity: 2.60–2.90

Formation & geological history

Formed as a secondary mineral by the action of percolating acidic aqueous solutions during the weathering and oxidation of pre-existing minerals. Typically found in arid regions within volcanic rocks or phosphorus-rich sedimentary rocks.

Uses & applications

Primarily used as a gemstone in jewelry (cabochons, beads, and carvings) and as an ornamental stone in interior design and spiritual practices.

Geological facts

Turquoise is one of the oldest gemstones in history, used by Egyptian pharaohs and Native American tribes for thousands of years. It is the traditional birthstone for December.

Field identification & locations

Identify in the field by its distinct robin's-egg blue color and waxy appearance. Often found in copper mining districts such as those in Arizona, Nevada, Iran, and China. Collectors look for 'spiderweb' matrix patterns caused by remnants of the host rock.