Turquoise

Physical Properties

Hardness: 5-6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually massive), Cleavage: Perfect (none seen in masses), Specific Gravity: 2.6-2.9

Formation & Geological History

Formed through the infiltration of meteoric water (rainwater) through copper-bearing aluminous rock. It occurs in arid climates as a secondary mineral in altered volcanic rocks and hydrothermal deposits.

Uses & Applications

Primarily used as an ornamental gemstone for jewelry (beads, cabochons), carvings, and historical decorative inlay.

Geological Facts

Turquoise is one of the oldest known gemstones, used by Ancient Egyptians as early as 3000 BCE. Its color comes from copper (blue) and iron or chrome (green).

Field Identification & Locations

Identify by its unique 'robin egg blue' color and dark 'matrix' (the webbing pattern of the host rock). Often found in the Southwestern USA, Iran, and China. Collectors look for vibrant color and lack of chalkiness.

Identified on: 4/26/2026

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