Composition: SiO2H2O a hydrated silica containing upto 10% waer in chemical composition
crystal System: non crystalline
Refractive Index: 1.45
Specific Gravity: 2.1
Hardness: 6.0
Lustre: Vitreous
Occurrence: Mainly New Soth Wales and Queensland in Australia, Brazil, Mexico (Fire Opal), USA
Opal
John Cadby Jewellers
Goldsmith, Silversmith,
Diamond Merchants, Appraiser & Engraver.
**************************************************************************
3, White Hart Yard, Trowbridge, Wiltshire. BA14 8BY
Tel: 01225 776322 E-Mail: John@Cadby.co.uk