mineral

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)

Hardness: 5-6 Mohs. Color: Sky blue to blue-green. Luster: Waxy to sub-vitreous. Crystal structure: Triclinic. Cleavage: Good to perfect (though rarely seen in cryptocrystalline forms). Specific gravity: 2.6-2.9.

Hardness: 5-6 Mohs
Color: Sky blue to blue-green
Luster: Waxy to sub-vitreous

Identified January 22, 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 as a secondary mineral by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals like copper sulfides and aluminum-rich silicates. It is typically found in arid regions within volcanic rocks or sedimentary phosphate deposits.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons, beads, and inlay) and ornamental carvings. It has been used for millennia for decorative and ritualistic purposes.

Geological facts

One of the first gemstones ever mined, with some mines in Egypt dating back to 3000 BCE. The name is derived from the French word for 'Turkish', as the stone originally reached Europe via Turkey from mines in Persia.

Field identification & locations

Identified by its unique 'robin's egg' blue color and often presence of 'matrix' (veins of host rock like limonite or quartz). Commonly found in Iran, the Southwestern United States, China, and Egypt. For collectors, look for uniform color and high density; it is often imitated by dyed Howlite or Magnesite.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

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

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral