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

John Cadby Jewellers
 Goldsmith, Silversmith,
Diamond Merchants, Appraiser & Engraver.
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3, White Hart Yard, Trowbridge, Wiltshire.  BA14 8BY
Tel: 01225 776322  E-Mail: John@Cadby.co.uk

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