Polished fossil Oncolite slab. ONC117 polished Noreena Jasper Dimensions approximately 120 mm x

Dimensions approximately 120 mm x 80 mm x 9

Western Australia

NJ411   Noreena Jasper slab

100 mm x 90 mm x 20 mm thick

Polished fossil Oncolite slab. ONC117 polished Noreena Jasper Dimensions approximately 120 mm xONC117. 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