Polished fossil Oncolite slab. ONC116 Rhodo 130 mm x 70 mm

130 mm x 70 mm  x 8

x 18 mm thick

DO229  Dendritic Opal slab

170 mm x 55 mm x 9

Dimensions at widest points approximately 135 mm x 125 mm x 8

Polished fossil Oncolite slab. ONC116 Rhodo 130 mm x 70 mmONC116. 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. 105 mm x 85 mm x 7 mm thick. Weighs 134 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 in