Polished Green Opal rock GRN96 Polished dendritic opal 5") Each piece approximately 3

5") Each piece approximately 3 - 4 cm at widest points

It weighs 3

Dimensions at widest points approximately 200 mm x 110 mm x 50 mm thick

Weighs 580 grams

Polished Green Opal rock GRN96 Polished dendritic opal 5") Each piece approximately 3GRN96 Green Opal & Magnesite rough rock, cut and polished on one side with a rough, naturally weathered back Dimensions at widest points approximately 120 mm x 55 mm x 35 mm thick Weighs 322 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.