mineral

Turquoise

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

Hardness: 5-6 (Mohs); Color: Sky blue, blue-green, or apple green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen in massive forms); Specific Gravity: 2.6-2.9

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

Identified July 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed by the percolation of meteoric waters through weathered aluminum-rich rocks in arid regions, where copper is present. It usually occurs as veinlets or nodules in volcanic or sedimentary rocks.

Uses & applications

Primarily used as a gemstone for jewelry, beads, and cabochons. It has been highly valued for thousands of years in ornamental and ritualistic objects.

Geological facts

Turquoise is one of the oldest known gemstones, used by Ancient Egyptians and Native American cultures. Its color can change over time if exposed to sunlight or body oils due to its porous nature.

Field identification & locations

Identify in the field by its distinctive robin-egg blue to green color and waxy texture. It is commonly found in Iran, Southwestern USA (Arizona, Nevada), and China. High-quality natural specimens are increasingly rare due to many commercial pieces being stabilized or dyed.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

sedimentary

Schist

Metamorphic

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

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Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

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Mineral/Rock