Polished Green Opal rock GRN115 alcheringa narrina 170 mm x 100 mm

170 mm x 100 mm x 9 mm

A trade name for metamorphosed magnesian tholeiite (basalt)

Dimensions at widest points approximately 200 mm x 120 mm x 60 mm thick

Dimensions at widest points approximately 160 mm x 75 mm x 12 mm thick

Approximate dimensions at widest points 140 mm  x 60 mm  x 43 mm thick

Polished Green Opal rock GRN115 alcheringa narrina 170 mm x 100 mmGRN115 Green Opal rough rock, cut and polished on one side with a rough, naturally weathered back Dimensions at widest points approximately 125 mm x 100 mm x 50 mm thick Weighs 686 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.