ULTRA HPQ QUALITY. High Purity Quartz Sand for the specialty glass (LCD, lenses, light bulbs, laboratory glassware), ceramics and quartzware markets. Typical level of impurities in the 50-100 ppm range with a D50 of 220 um. High Purity Quartz Powder for the High Purity Filler (HPF) (paint, insulation, resins, abrasives), ceramics and EMC ...Web