Polished fossil Oncolite. ONC110 Orbicular Granite OJ199 A rough rock

OJ199  A rough rock

POP195   Brecciated Pink Opal slab

165 mm x 120 mm x 25 mm

Pilbara region of Western Australia

Polished fossil Oncolite. ONC110 Orbicular Granite OJ199 A rough rockONC110. 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. 125 mm x 70 mm x 8 mm thick. Weighs 172 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