Welcome to Imerys Performance Minerals

Mechanical properties

Mechanical properties Imerys wollastonites - excellent reinforcing agents in traditional ceramic bodies and glazes

Due to their unique acicular structure, Imerys wollastonites are excellent low loss on ignition (LOI) reinforcing agents improving the mechanical properties of ceramic green bodies, engobes and glazes.

Green bodies

Imerys wollastonites are excellent fluxing agents and low LOI replacements for other calcium oxides in traditional ceramics bodies.

Added to green bodies, Imerys wollastonites:

  • Increase green and fired body toughness
  • Improve impact strength
  • Reduce firing shrinkage
  • Suppress warpage
  • Prevent slumping

Control of particle size and shape is the most important parameter in ceramic bodies. Coarser and more acicular wollastonite grades will be more effective reinforcement agents here.

We recommend our Nyad® M100 and Nyad® M200 grades for reinforcement in traditional ceramic green bodies.

SEM photograph of Nyad coarse wollastonite
Coarser, more acicular grades are more effective reinforcement agents


Used as a fluxing agent in glazes, Imerys wollastonite lowers the effective melting temperature of feldspar by up to 100ºC. This reduces firing costs and yields more durable glazes. Our wollastonites also have a loss on ignition (LOI) typically below 0.5%, meaning minimum CO2 is emitted during firing compared to other materials, improving the strength of the glaze.

We recommend our Nyad® M325 and Nyad® M400 for glazes.


Imerys wollastonites are suited for the production of:

  • Wall and floor tiles
  • Sanitaryware
  • Tableware