WOLLASTONITE POWDER Wollastonite powder is natural calcium silicate mineral. It is white crystalline powder, needle-like granules, with pearl and glass luster and good whiteness Melting temperature 1540 ? , Mohs hardness is 4.5-6.0, Density 2.87-3.09, low heat swelling and low loss on ignition. Technical Specifications Items - Inspection results Appearance - white crystalline powder Whiteness - 90-94 SiO2 - 48-51% CAO - 47% AL2O3 -