mineral

Turquoise

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

Hardness: 5-6 (Mohs), Color: Blue to green (sky blue, teal, apple green), Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), Cleavage: None, Specific gravity: 2.6-2.9

Identified May 13, 2026More mineral →

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Physical properties

Formation & geological history

Formed by the percolation of acidic aqueous solutions through preexisting minerals during the weathering and oxidation of copper deposits in arid environments.

Uses & applications

Primarily used in jewelry (cabochons, beads, inlay) and ornamental carvings; highly valued in Native American and Middle Eastern crafts.

Geological facts

Turquoise is one of the oldest gemstones in human history; it was mined by Ancient Egyptians as early as 3000 BCE and used in the burial mask of King Tutankhamun.

Field identification & locations

Identify in the field by its distinct hue and waxy surface; often found in desert regions like the Southwestern US and Iran near limonite or copper sites.

Other mineral specimens

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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

Green Apatite on Albite

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

mineral