Polished Green Opal slab GRN118 purple OPS116 Opalised Serpentine rough rock

OPS116  Opalised Serpentine rough rock

120 mm x 70 mm x 45 mm thick

Dimensions at widest points approximately 100 mm  x 35 mm wide x 7 mm thick

Dimensions at widest points approximately 120 mm x 35 mm x 10 mm thick

Asperia ashburtonia from the Proterozoic "Duck Creek Dolomite"

Polished Green Opal slab GRN118 purple OPS116 Opalised Serpentine rough rockGRN118 Green Opal slab, cut and polished on one side . Dimensions at widest points approximately 140 mm x 110 mm x 11 mm thick Weighs 287 grams. Green Opal occurs at a location south of Kalgoorlie in the Eastern Goldfields of Western Australia. The green colouration is caused by traces of nickel and or chromium. Sometimes it exhibits striking contrasting veins of magnesite..