A chemical compound, with chemical formula CaCO3. Calcium carbonate is widely used as an extender in paints, in particular matte emulsion paint where typically 30% by weight of the paint is either chalk or marble. Calcium carbonate is known as whiting in ceramics/glazing applications, where it is used as a common ingredient for many glazes in its white powdered form. When a glaze containing this material is fired in a kiln, the whiting acts as a flux material in the glaze. In North America, calcium carbonate has begun to replace kaolin in the production of glossy paper. Europe has been practicing this as alkaline papermaking or acid-free papermaking for some decades. Precipitated calcium carbonate (PCC), has a very fine and controlled particle size, on the order of 2 micron in diameter, useful in coatings for paper.
New Ultra Fine Calcium Carbonate, is now available. It is an extra light PCC, low lead calcite which is a 1.6 micron scalenohedral particle. This open clustered needles results in the lowest density VICALity PCC grade with the highest absorption.
Calcium Carbonate is also known as gilder's chalk and available in two purity levels: Standard and USP Ultra Fine