mineral

Turquoise

Turquoise, CuAl6(PO4)4(OH)8·4H2O

Hardness: 5-6 Mohs; Color: Turquoise blue, sky blue, or blue-green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic (usually massive/cryptocrystalline); Cleavage: Perfect but rarely seen; Specific Gravity: 2.6-2.9

Hardness: 5-6 Mohs
Color: Turquoise blue, sky blue, or blue-green
Luster: Waxy to subvitreous

Identified May 27, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals (secondary mineral). Commonly found in arid environments within volcanic or sedimentary rocks rich in aluminum and phosphorus near copper deposits.

Uses & applications

Primarily used as an ornamental gemstone for jewelry (cabochons, beads, inlays) and decorative items. Highly valued in cultural craft, particularly in Southwestern United States and Middle Eastern traditions.

Geological facts

Turquoise has been mined since at least 3000 BCE by Ancient Egyptians. Its name is derived from the French 'turquois' meaning 'Turkish', as the stone first reached Europe via Turkey from mines in Persia.

Field identification & locations

Identify in the field by its distinct robin's-egg blue or green color and its association with copper-rich arid regions like Arizona, Nevada, Iran, and China. Collectors look for 'matrix' (host rock patterns) spider-webbing.