Wollastonite

Wollastonite is calcium silicate (CaSiO3) which forms as aggregates of needle-shaped crystals. Crystals with high aspect ratio (long needle shapes) are used as an asbestos fibre substitute, and for reinforcing in thermoplastics and thermoset polymers. Wollastonite with a low aspect ratio is used as a general filler, and in some ceramic bodies where its low coefficient of thermal expansion reduces shrinkage, cracking, and crazing.

The physical properties and chemical components