mineral

Turquoise

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

Hardness: 5-6 (Mohs), Color: cyan/blue-green/sky blue, Luster: waxy to subvitreous, Crystal structure: triclinic, Cleavage: perfect to fair (though rarely seen in cryptocrystalline form), SG: 2.6-2.9

Identified June 13, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 5-6 (Mohs), Color: cyan/blue-green/sky blue, Luster: waxy to subvitreous, Crystal structure: triclinic, Cleavage: perfect to fair (though rarely seen in cryptocrystalline form), SG: 2.6-2.9

Formation & geological history

Formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals; often found in arid environments within volcanic rocks or phosphorus-rich sedimentary rocks.

Uses & applications

Predominantly used as a gemstone for jewelry and ornamental carvings. Historically significant in Native American, Egyptian, and Persian cultures.

Geological facts

Turquoise is one of the oldest known gemstones used by humans. The name comes from the French 'turquois' meaning 'Turkish', as the stone originally reached Europe via Turkey from mines in Persia.

Field identification & locations

Identify by its unique sky-blue to green-blue color and waxy luster. In the field, look for thin veins or nodules in weathered volcanic host rocks. Often associated with copper deposits in Arizona, Nevada, and New Mexico.

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

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic