Calcium Carbonate
A 325 mesh material may have a mean particle size of only 10 microns (or even less), whereas a 200 mesh grade might be two or three times that (yet both powders feel the same). In glazes that contain both calcium carbonate and silica it is preferable to source as much as possible of the SiO 2 from wollastonite instead. This is because the SiO 2 in wollastonite is taken into solution in the ...