Polished fossil Oncolite slab. ONC112 ashburton agate Weighs 135 grams

Weighs 135 grams

Dimensions at widest points approximately 165 mm high x 100 mm x 95 mm thick

Weighs 387 grams

160 mm x 110 mm x 90 mm

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

Polished fossil Oncolite slab. ONC112 ashburton agate Weighs 135 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