Polished fossil Oncolite slab. ONC112 ashburton agate Dimensions at widest points approximately

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

Dimensions approximately 110 mm x 90 mm x 9 mm thick

160 mm x 110 mm x 90 mm

TI369   Tiger Iron rough rock

Weighs 135 grams

Polished fossil Oncolite slab. ONC112 ashburton agate Dimensions at widest points approximatelyONC112. 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