Polished fossil Oncolite slab. ONC117 chrysoprase Polished petrified wood slab

Polished petrified wood slab

Dimensions approximately 130 mm x 100 mm x 50 mm thick

Face is approximately 105mm x 50mm and  7mm thick

Weighs 165 grams

It weighs 230 grams

Polished fossil Oncolite slab. ONC117 chrysoprase Polished petrified wood slabONC117. 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. 160 mm x 80 mm x 8. 5 mm thick. Weighs 217 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