Polished fossil Oncolite slab. ONC112 prehnite Weighs 723 grams

Weighs 723 grams

OJ194  A slab

Dimensions at widest points approximately 130 mm x 100 mm x 70 mm thick

Very rare fossil stromatolite slab polished on one side

Polished fossil Oncolite slab. ONC112 prehnite Weighs 723 gramsONC112. 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