... stone; 1-3cm to 10-100cm; natural stone,non-polluting; 3,000mt/month ISO9001-2000 certified company Pumice Character,1), Light ... , high in hardness;2), Natural stone,non-polluting, non-radioactive;3), Acid resistance, Corrosion resistance;4), An ideal natural, green, ... : Red,Brown,Black and white, off-white.(Normally brown mixed black and white mixed gray).Size:2-3MM,5-10MM,10-15MM,30-50MM ...