Fossil Oncolite polished slab.
From the Miocene "Trealla Limestone" north of Carnarvon, Western Australia .
Age is approx. 15 million years.
Approx. 125 mm x 80 mm x 8 mm thick.
Weighs 174 grams.
Polished Green Opal GREEN58
Polished Green Opal GREEN57
Polished Green Opal GREEN56
Polished Crazy Lace Agate CLA237