Oolitic Limestone – Yorkshire (1kg)
Oolitic Limestone. Jurassic (Oxfordian) in age from the Malton Oolite & Coral Rag member. Generally much harder than the oolitic example from Gloucestershire. Supplied by weight with the size of pieces being random, comes in a polythene bag with an information label.
Oolitic limestone is a carbonate rock made up mostly of ooliths (or ooids) which are sand-sized carbonate particles (0.25 -2.0mm) built up of concentric shells of precipitated calcium carbonate CaCO3. These layers were formed around grains of sand or shell fragments that were rolled around on a shallow sub tropical sea floor, gathering layer after layer of carbonate. This pale grey limestone is from the Malton Oolite & Coral Rag (Oxfordian) member of the Jurassic outcrops around Pickering in Yorkshire. Examples may also locally contain abundant shell fragments.