Polished fossil Oncolite slab. ONC112 prehnite Dimensions at widest points approximately

Dimensions at widest points approximately 120 mm x 70 mm  x 7 mm thick

135 mm x 85 mm x 50 mm thick

cut and polished  on one side with a natural back and a cut base to stand as a display specimen

MC106 Marillana Conglomerate rough rock

Approximate weight of each piece is between 90 and 170 grams

Polished fossil Oncolite slab. ONC112 prehnite Dimensions at widest points approximatelyONC112. 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. 145 mm x 105 mm x 8 mm thick. Weighs 285 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