Polished fossil Oncolite slab. ONC116 fossil stromatolite POP178 Pink Opal slab

POP178   Pink Opal slab

PU137  Purple Chalcedony slab

Weighs 539 grams

145 mm x 105 mm x 8 mm thick

135 mm x 75 mm x 9 mm

Polished fossil Oncolite slab. ONC116 fossil stromatolite POP178 Pink Opal slabONC116. 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