Polished fossil Oncolite slab. ONC116 toredo 190 mm x 190 mm

190 mm x 190 mm x 70 mm

Weighs 585 grams

One edge slightly unpolished

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

Magnesite (Lemon chrysoprase) rough rock

Polished fossil Oncolite slab. ONC116 toredo 190 mm x 190 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