mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminum)
Hardness: 5-6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually massive); Specific gravity: 2.6-2.9.
- Hardness
- 5-6 (Mohs)
- Color
- Sky blue to blue-green
- Luster
- Waxy to subvitreous
Identified More mineral →
Explore Turquoise in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-6 (Mohs); Color: Sky blue to blue-green; Luster: Waxy to subvitreous; Crystal system: Triclinic (usually massive); Specific gravity: 2.6-2.9.
Formation & geological history
Turquoise is a secondary mineral formed by the percolation of meteoric water through aluminous rock in the presence of copper minerals, usually in arid or desert climates.
Uses & applications
Primarily used as a gemstone for jewelry (beads, cabochons, and inlays) and for ornamental carvings.
Geological facts
It is one of the oldest gemstones used in human history, dating back to ancient Egypt (c. 3000 BCE). It is porous and can change color if exposed to oils, perspiration, or light.
Field identification & locations
Identify by its waxy luster and characteristic color. It is often found in Nevada, Arizona, New Mexico, Iran, and China. Collectors should watch for 'stabilized' or dyed howlite imitations.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
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