Polished fossil Oncolite slab. ONC117 polished Noreena Jasper 100 mm x 90 mm

100 mm x 90 mm x 20 mm thick

Dimensions approximately 80 mm x 70 mm x 65 mm deep

It weighs 185 grams

Dimensions approximately 120 mm x 80 mm x 9

100 mm x 80 mm x 55 mm

Polished fossil Oncolite slab. ONC117 polished Noreena Jasper 100 mm x 90 mmONC117. 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. 160 mm x 80 mm x 8. 5 mm thick. Weighs 217 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