Turquoise

Physical Properties

Hardness: 5-6 (Mohs scale); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen)

Formation & Geological History

A secondary mineral formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals (aluminum-rich rocks and copper sulfides). Most deposits are relatively young geologically, typically found in arid regions.

Uses & Applications

Primarily used as an ornamental stone and in jewelry. Historically used for talismans and amulets.

Geological Facts

Turquoise is one of the first gemstones ever mined, with evidence showing mining in Egypt as early as 3000 BCE. Its name comes from the French 'turquoise', meaning 'Turkish', as it reached Europe via Turkey from Persian mines.

Field Identification & Locations

Identify by its unique blue-green color and 'matrix' (web-like patterns of host rock). Often found in arid climates like the Southwestern US, Iran, and China. Collectors look for vibrant 'sleeping beauty' blue or high-contrast matrix patterns.

Identified on: 4/21/2026

Mode: Standard