Polished fossil Oncolite slab. ONC115 asperia ashburtonia Approximate dimensions at widest points

Approximate dimensions at widest points 130 mm  x 115 mm  x 12

Dimensions at widest points approximately 110 mm x  100 mm x 9 mm thick

Weight :  168 grams

EU105  4 pieces of Eucryptite rough rock

Dimensions at widest points approximately 80 mm x 40 mm x 16 mm thick

Polished fossil Oncolite slab. ONC115 asperia ashburtonia Approximate dimensions at widest pointsONC115. 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. 170 mm x 70 mm x 7. 5 mm thick. Weighs 211 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