Polished fossil Oncolite slab. ONC114 beryl BJ136 Polished "Black Jade" A

BJ136 Polished "Black Jade" A trade name for metamorphosed magnesian tholeiite (basalt)

Dimensions at widest points approximately 80 mm x 55 mm x 40 mm thick

MN132  Magneprase slab

CW132   Chinese Writing Stone rough rock

KO106  Killaloe Opal slab

Polished fossil Oncolite slab. ONC114 beryl BJ136 Polished "Black Jade" AONC114. 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. 150 mm x 100 mm x 7. 5 mm thick. Weighs 241 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