Turquoise

Color: Blue, Green
Category: Phosphate minerals
Formula: CuAl6(PO4)4(OH)8·4H2O
Hardness: 5 – 6
Density: 2.6-2.8, average 2.7
Crystal: Triclinic
Luster: Waxy
Treatment: None
Origin: This material can be found in many locations around the world. The stones in the picture are from Armenia.