Polished fossil Oncolite slab. ONC116 Nickeloan magnesite 150 mm x 80 mm

150 mm x 80 mm x 16 mm thick and weighs 381 grams

OG209   A matching pair of polished Orbicular Granite halves with natural rough backs

GRN96  Green Opal & Magnesite rough rock

OJ168  A slab

110 mm x 100 mm x 35 mm thick

Polished fossil Oncolite slab. ONC116 Nickeloan magnesite 150 mm x 80 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