mineral

Turquoise

Turquoise (Hydrated phosphate of copper and aluminium), CuAl6(PO4)4(OH)8·4H2O

Hardness: 5–6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic; Specific Gravity: 2.6–2.9; Cleavage: Good to perfect (though rarely seen in massive specimens)

Hardness: 5–6 (Mohs)
Color: Sky blue to blue-green
Luster: Waxy to subvitreous

Identified July 3, 2026More mineral →

Explore Turquoise in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

A secondary mineral formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing copper-bearing minerals. Typically found in arid regions within volcanic rocks or sedimentary phosphate-rich layers.

Uses & applications

Primarily used in jewelry, decorative carvings, and as a gemstone for collectors. Historically used in amulets and architectural inlay.

Geological facts

Turquoise is one of the oldest known gemstones, used by the Egyptians as early as 3000 BCE. Its name comes from the French 'turqueise', meaning 'Turkish', as it first reached Europe via Turkey from Persian mines.

Field identification & locations

Identified by its unique 'robin's egg' blue color and often presence of a dark matrix (veins of host rock). It is commonly found in the Southwestern USA, Iran, and China. Collectors should look for vibrancy of color and lack of artificial stabilization.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock

Granite

Granite (Phaneritic intrusive igneous rock)

igneous