Polished fossil Oncolite slab. ONC115 lace agate KO109 Killaloe Opal slab

KO109  Killaloe Opal slab

Weighs 488 grams

NJ441   Noreena Jasper slab

Dimensions at widest points approximately 130 mm  x 100 mm x 8 mm thick

70 mm x 50 mm  x 30 mm

Polished fossil Oncolite slab. ONC115 lace agate KO109 Killaloe Opal slabONC115. 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. 170 mm x 70 mm x 7. 5 mm thick. Weighs 211 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