Polished Green Opal slab GRN93. aquamarine Dimensions approximately 110 mm x

Dimensions approximately 110 mm x 70 mm x 50 mm thick

Approximate dimensions at widest points 145 mm  x 65 mm  x 12 mm thick

Dimensions at widest points approximately 200 mm high x 100 mm wide x 90 mm thick

a small abandoned gold mining centre in the Midwest region of Western Australia

NJ432  A rough rock

Polished Green Opal slab GRN93. aquamarine Dimensions approximately 110 mm xGRN93 Green Opal & Magnesite slab, cut and polished on one side . Dimensions at widest points approximately 115 mm x 90 mm x 9 mm thick Weighs 155 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..