Calcium Carbonate

This natural material is a white powder or a colourless, crystalline compound found in limestone, among other places. It is very soft, and for this reason, it is mainly used for cleaning stone or thin-panelled alloy structures. Occasionally, it is an inexpensive substitute for bicarbonate of soda abrasive, since the finer grades of calcium carbonate are partially dissolvable in water. Calcium carbonate is available as a food grade, so it can be used for blasting in some food and brewing applications.