mineral

Turquoise

Hydrous phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)

Hardness: 5-6 (Mohs scale), Color: Sky blue to apple green, Luster: Waxy to sub-vitreous, Crystal structure: Triclinic (usually cryptocrystalline), Specific gravity: 2.6-2.9

Identified April 10, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs scale), Color: Sky blue to apple green, Luster: Waxy to sub-vitreous, Crystal structure: Triclinic (usually cryptocrystalline), Specific gravity: 2.6-2.9

Formation & geological history

Formed by the percolation of meteoric waters through weathered volcanic rocks in arid climates. It often occurs as veins or crusts in association with copper deposits and aluminum-rich rocks.

Uses & applications

Predominantly used for jewelry, lapidary arts, and ornamental carvings. Historically used for talismans and amulets by ancient civilizations.

Geological facts

Turquoise is one of the oldest gemstones in human history, mined by the Ancient Egyptians as early as 3000 BCE. Its color is highly dependent on copper (blue) and iron or chrome (green).

Field identification & locations

Identify in the field by its distinctive robin-egg blue to lime green color and waxy appearance. Commonly found in the Southwest USA, Iran, and China. Collectors look for stable specimens with unique matrix patterns.

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