Turquoise
Formula:CuAl6(PO4)4(OH)8 · 4H2O
Colour:bright blue, sky-blue, pale green, blue-green, turquoise-blue, apple-green, green-gray
Classification:Phosphates
Lustre:Sub-Vitreous, Resinous, Waxy, Dull, Earthy
Crystal System:Triclinic
Hardness:5-6
Specific Gravity:2.6-2.8