Polished fossil Oncolite. ONC109 mookatite Dimensions at widest points approximately

Dimensions at widest points approximately 110 mm x 85 mm x 9 mm thick

185 mm x 75 mm x 65 mm

Large reserves of this stone occur in Western Australia

Good example of fault displacement

195 mm x 135 mm x 14 mm

Polished fossil Oncolite. ONC109 mookatite Dimensions at widest points approximatelyONC109. Fossil Oncolite polished slab. From the Miocene "Trealla Limestone" north of Carnarvon, Western Australia . Age is approx. 15 million years. Dimensions at widest points approx. 150 mm x 65 mm x 6. 5 mm thick. Weighs 117 grams. Oncolite is a limestone composed largely of oncoidsrounded, coated grains that grow as thin layers of lime mud accumulate around a tiny nucleus (such as a sand grain or shell fragment) under microbial influence. Formed