Polished fossil Oncolite. ONC111 outback jasper cut and polished on one

cut and polished on one side at right angles to crystal growth

OG172   Polished orbicular granite with natural rough back

Dimensions at widest points approximately 115 mm high x 65 mm x 45 mm thick

55 mm x 50 mm  x 17 mm

Dimensions at widest points approximately 170 mm x 150 mm

Polished fossil Oncolite. ONC111 outback jasper cut and polished on oneONC111. 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. 140 mm x 100 mm x 6. 5 mm thick. Weighs 204 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