SiO2 Quartz powder,sand Has different meshes, from10 mesh to 600 ... . Their mathing whiten from 90% to 95% Certificate of Analysis Sio2≥ 99% Fe2O3≤ 0.1% whiteness: 91-92% Moisture: 0.08 ... the correctingGrind materials: making grindstone, oilstone, sandpaper, silicon carbonate white SiO2 Quartz powder