Polished fossil Oncolite slab. ONC116 toredo Dimensions at widest points approximately

Dimensions at widest points approximately 180 mm x 130 mm x 60 mm thick

One edge slightly unpolished

Magnesite (Lemon chrysoprase) rough rock

Dimensions approximately 115 mm x 55 mm x 30 mm deep

TIR175 Tiger Iron rough rock

Polished fossil Oncolite slab. ONC116 toredo Dimensions at widest points approximatelyONC116. 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