Polished fossil Oncolite slab. ONC117 polished Noreena Jasper NJ411 Noreena Jasper slab

NJ411   Noreena Jasper slab

125 mm x 75 mm  x 9

Dimensions approximately 120 mm x 80 mm x 9

100 mm x 90 mm x 20 mm thick

It weighs 185 grams

Polished fossil Oncolite slab. ONC117 polished Noreena Jasper NJ411 Noreena Jasper slabONC117. 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