Polished Green Opal rock GRN102 magneprase Dimensions at widest points approximately

Dimensions at widest points approximately 150 mm x 110  mm x 7 mm thick

Weighs 431 grams

OJ164  A rough rock

Weighs 129 grams

Dimensions at widest points approximately 150 mm x 30 mm x 7

Polished Green Opal rock GRN102 magneprase Dimensions at widest points approximatelyGRN102 Green Opal & Magnesite rough rock, cut and polished on one side with a rough, naturally weathered back Dimensions at widest points approximately 90 mm x 50 mm x 40 mm thick Weighs 340 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.