... produced using fused silica lump as material, it is white powder of high purity and amorphous, with the quality of low linear expansion ... /16, 16/30, 30/60, 60/120, 100mesh, 200mesh, 325mesh;*Micro powder is available as required.Applications:1. Used in precision casting ... . Plastic seal;6. Epoxy resin;7.Quartz rubber;8. Pouring. High Purity Fused Silica SiO2 99.9% Min