Whiting, Calcium Carbonate

Whiting- Calcium Carbonate – CaCO₃ (m.p. 4650^o F/2570^o C) is a finely ground powder composed essentially of pure Calcium Carbonate derived from Limestone, Chalk, or Marble. It is the most common source of Calcium in a glaze and clay body. In stoneware glazes (cone 7-12), it promotes a matt finish and produces a harder and more chemically resistant glaze. In stoneware bodies (cone 7-12) it acts as a flux (typically >3%), and it will increase shrinkage and strength by lowering the vitrification point and decreasing porosity.