Polished Green Opal slab GRN79
GRN79 Green Opal & Magnesite slab, cut and polished on one side .
Dimensions at widest points approximately 140 mm x 80 mm x 10 mm thick
Weighs 169 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.