Polished fossil Oncolite slab. ONC114 dendrites Dimensions at widest points approximately

Dimensions at widest points approximately 120 mm x 80 mm x 10 mm thick

Dimensions at widest points approximately 165 mm x 105 mm x 9 mm thick

80 mm x 65 mm x 45 mm

It weighs 476 grams

NJ433  A rough rock

Polished fossil Oncolite slab. ONC114 dendrites Dimensions at widest points approximatelyONC114. 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 100 mm x 7. 5 mm thick. Weighs 241 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