CaO.SiO2 In low fired ceramics it reduces drying and firing shrinkage and warpage. It promotes lower moisture and thermal expansion in firing. Valuable component of tile bodies as it releases no gasses and helps other gasses vent out early. Stronger flux over 1100oC. Wollastonite is a useful alternative to whiting when pinholing is a problem and where talc would introduce too much MgO. Often used to supply CaO in a more easily melted form in stain and frit formulations.Glass jar is for illustration purposes only.