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

NJ411   Noreena Jasper slab

Dimensions at widest points approximately 140 mm x 120 mm and 11 mm thick

125 mm x 75 mm  x 9

Weighs 52 grams

100 mm x 80 mm x 55 mm

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