Polished Green Opal rock GRN103 alcheringa narrina 110 mm x 110 mm

110 mm x 110 mm x 8 mm

It does occur in the same geological "Marra Mamba Iron Formation"

TIR139 Tiger Iron rough rock

Dimensions approximately 120 mm x 65 mm x 8 mm thick

quartz and a small amount of red rubellite

Polished Green Opal rock GRN103 alcheringa narrina 110 mm x 110 mmGRN103 Green Opal & Magnesite rough rock, cut and polished on one side with a rough, naturally weathered back Dimensions at widest points approximately 170 mm x 70 mm x 80 mm thick Weighs 763 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.