Polished fossil Oncolite. ONC109 Polished rock. Weighs 752 grams

Weighs 752 grams

Weight of both is 555 grams

Dimensions at widest points approximately 100 mm high x 100 mm x 30 mm thick

Dimensions at widest points approximately 70 mm x 35 mm x 30 mm thick

Polished fossil Oncolite. ONC109 Polished rock. Weighs 752 gramsONC109. 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