Composition: CuAl6(PO4)4(OH)8.5H2O
crystal System:  Trigonal
Habit: Botryoidal.
Refractive Index: 1.61-16.5(only single shadow edge at 1.62 is normally seen on the refractometer)
Specific Gravity: 2.6-2.9 depending on source
Hardness:  5.5-6.0
Fracture: Concohoidal
Lustre:  Waxy
Absorption Spectrum: Lines in the blue-violet at 420 and 432nm may be visible
Occurrence:  Afghanistan, China (Tibet), Iran, Israel (Sinai), USA

Turquoise