... semitransparent and/or whitish crystals SIZES (US mesh - stock items): 60/80, 80/100, 100/120, 120/140, 140/170, 170/200, 200 ... , 14-20, 15-25, 20-30, 22-36, 20-40, 30-40, 40-60Other micron sizes available on requestReactivity test :2000-2800 times ...