Polished fossil Oncolite slab. ONC113 crystoprase Weighs 61 grams

Weighs 61 grams

Slightly tapering thickness of 8 - 10 mm

chalcedony and magnesite in the one piece

BM327  Brecciated  Mookaite rock

Dimensions at widest points approximately 125 mm high x 95 mm  x 40 mm thick

Polished fossil Oncolite slab. ONC113 crystoprase Weighs 61 gramsONC113. 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. 165 mm x 160 mm x 9 mm thick. Weighs 449 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