mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Hardness: 5-6 (Mohs), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually massive), Specific Gravity: 2.6-2.9
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Physical properties
Hardness: 5-6 (Mohs), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually massive), Specific Gravity: 2.6-2.9
Formation & geological history
Secondary mineral formed by the percolation of acidic aqueous solutions during the weathering and oxidation of pre-existing minerals containing copper, aluminum, and phosphorus in arid environments.
Uses & applications
Primarily used as a gemstone for jewelry, beads, and inlay work. Highly valued for ornamental and cultural artifacts.
Geological facts
Turquoise is one of the oldest gemstones in human history, used by Ancient Egyptians, Aztecs, and the indigenous peoples of the American Southwest for over 3,000 years.
Field identification & locations
Identified by its unique waxy luster and robin's egg blue color. Frequently found in copper mining districts like those in Arizona, Nevada, Iran, and China. Often contains brown or black 'matrix' from the host rock.
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Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous