![Turquoise (Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]) — mineral](https://media.rockidentification.com/4d790efd-b222-4ebe-9d7d-8d640730eaed-compressed.jpg)
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 sub-vitreous; Crystal structure: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen in massive forms); Specific Gravity: 2.6–2.9
- Hardness
- 5-6 (Mohs scale)
- Color
- Sky blue to apple green
- Luster
- Waxy to sub-vitreous
Identified More mineral →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-6 (Mohs scale); Color: Sky blue to apple green; Luster: Waxy to sub-vitreous; Crystal structure: Triclinic (usually cryptocrystalline); Cleavage: Perfect (rarely seen in massive forms); 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. Typically found in arid regions within volcanic rocks or sedimentary limestones near copper deposits.
Uses & applications
Primarily used as a gemstone in jewelry (cabochons and beads) and ornamental carvings. Historically used as a pigment and for architectural decoration in various cultures.
Geological facts
One of the oldest known gemstones, it was being mined in the Sinai Peninsula by 3000 BCE. The name is derived from the French word 'turquois', meaning 'Turkish', as it was originally brought to Europe via trade routes through Turkey.
Field identification & locations
Identify by its unique 'robin's egg' blue color and often the presence of a dark 'matrix' (host rock veins). Commonly found in the Southwestern USA, Iran, China, and Egypt. Collectors should look for natural, untreated stones versus dyed 'howlite' or plastic imitations.
More like this
Other mineral specimens
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](https://media.rockidentification.com/2391a63f-fb20-47d5-af9a-2035851eb32e-thumbnail.jpg)
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
mineral
Epidote
Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)
mineral