3-5 mm Pumice stone 1-3cm to 10-100cm; natural stone,non-polluting; 3,000mt/month ISO9001-2000 certified company Pumic stone; 1-3cm to ... certified company Pumice Character,1), Light in weight, high in hardness;2), Natural stone,non-polluting, non-radioactive;3), Acid resistance, Corrosion ... -white.(Normally brown mixed black and white mixed gray).Size:2-3MM,5-10MM,10-15MM,30-50MM,50-80MM,80-100MM ...