mineral

Turquoise

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

Hardness: 5-6 (Mohs scale); Color: Sky blue to apple green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen due to fine grain); Specific Gravity: 2.6-2.9

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

Identified April 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the infiltration of acidic aqueous solutions during the weathering and oxidation of pre-existing copper minerals in arid or semi-arid environments. It typically fills veins and cavities in host rocks like trachyte or sandstone.

Uses & applications

Primarily used as a gemstone for jewelry (beads, cabochons, inlays), ornamental carvings, and historical talismans.

Geological facts

Turquoise is one of the oldest gemstones in history; it was mined by Ancient Egyptians as early as 3200 BC. The name comes from the French phrase 'pierre turquoise', meaning 'Turkish stone', as it was first brought to Europe through Turkey.

Field identification & locations

Identify by its unique 'robin's egg' blue color and dark matrix (limonite/sandstone) webbing. Commonly found in Arizona, Nevada, Iran, and China. Collectors should look for vibrant, uniform color and high density; porous or dyed fakes are common (Howlite is often dyed to look like turquoise).

Other mineral specimens

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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