mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
AI-generated identification · may be incorrectHardness: 5-6 Mohs; Color: Sky blue to apple green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic (usually massive); Specific Gravity: 2.6-2.9
- Hardness
- 5-6 Mohs
- Color
- Sky blue to apple 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 apple green; Luster: Waxy to subvitreous; Crystal Structure: Triclinic (usually massive); Specific Gravity: 2.6-2.9
Formation & geological history
Formed 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 phosphate deposits.
Uses & applications
Primarily used as a gemstone in jewelry (cabochons, beads, inlays) and for decorative carvings or ornamental objects.
Geological facts
Turquoise is one of the oldest known gemstones, used by Ancient Egyptians and Native Americans for over 3,000 years. Its name comes from the French 'turquois' meaning Turkish, as it first reached Europe via Turkey.
Field identification & locations
Identified by its distinctive blue-green hue and waxy luster. Common in the Southwestern US (Arizona, Nevada) and Iran. Watch for 'Howlite' dyed to look like turquoise; real turquoise is harder and color does not rub off with acetone.
