Polished Green Opal rock GREEN83 purple Dimensions approximately 120 mm x

Dimensions approximately 120 mm x 70 mm x 8 mm thick

Dimensions approximately 100 mm x 90 mm x 80 mm thick

CC120  Chrome chalcedony slab

Weighs 479 grams

Dimensions at widest point approximately 235 mm x 60 mm x 13 mm

Polished Green Opal rock GREEN83 purple Dimensions approximately 120 mm xGREEN83 Green Opal & Magnesite rough rock, cut and polished on one side with a rough, naturally weathered back Dimensions at widest points approximately 180 mm x 100 mm x 75 mm thick Weighs 1,834 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.