mineral

Turquoise in Matrix

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

Hardness: 5-6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal Structure: Triclinic (usually cryptocrystalline), Specific Gravity: 2.6–2.9

Identified April 19, 2026More mineral →

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Physical properties

Hardness: 5-6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal Structure: Triclinic (usually cryptocrystalline), Specific Gravity: 2.6–2.9

Formation & geological history

Formed as a secondary mineral by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals; often found in arid climates within volcanic rocks or limestones.

Uses & applications

Primarily used as a gemstone for jewelry, ornamental carvings, and as a highly prized collector's mineral.

Geological facts

Turquoise is one of the oldest gemstones in human history; it was mined by the Ancient Egyptians in the Sinai Peninsula as early as 3000 BCE and is sacred to many Native American cultures in the Southwest US.

Field identification & locations

Identify in the field by its distinct robin's egg blue or greenish-blue color and waxy appearance, often accompanied by dark 'matrix' veins of host rock like limonite or chert. Common in Southwestern USA, Iran, and China.

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sedimentary

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Metamorphic

Epidote

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

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Nephrite Jade

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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