Turquoise

Physical Properties

Hardness: 5-6 (Mohs scale); Color: Sky blue, blue-green, or apple green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic (rarely seen as crystals); Cleavage: Perfect but usually not visible in massive specimens; Specific Gravity: 2.6–2.9.

Formation & Geological History

A secondary mineral formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing copper minerals in arid environments. Often found as veins or crusts in altered volcanic rocks.

Uses & Applications

Primarily used in jewelry for cabochons, beads, and inlay. Also highly valued by mineral collectors and used in decorative art.

Geological Facts

Turquoise has been mined for over 3,000 years; the ancient Egyptians used it in burial masks, and it has deep cultural significance to many Native American tribes in the Southwestern US.

Field Identification & Locations

Identify by its unique 'robin's egg' blue color and often present dark spider-web-like matrix (limonite or manganese oxide veinlets). Commonly found in arid regions like Iran, Egypt, and the Southwestern United States (Arizona, Nevada, New Mexico).

Identified on: 4/27/2026

Mode: Standard