Polished Green Opal slab GRN93. aquamarine a small abandoned gold mining

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

Bauxite is the main raw material used in the commercial production of aluminium

Dimensions approximately 110 mm x 70 mm x 50 mm thick

Weighs 315 grams

Polished Green Opal slab GRN93. aquamarine a small abandoned gold miningGRN93 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..