1.ISO9001:2008 2..SiO2:99.31%,Moh: 8 3.Long using life: 3years 4.Size:2-4,4-6,6-8,8-10,10-12,12-15cm Natural Pebble Stone1.ProductPebbles/Natural pebbles/ Sea pebbles/Silica pebbles/Cobblestone/River pebbles/Pebbles for ceramic industry2.size unit:cmSmall sizeMiddle sizeBig size2-46-810-124-68-1012-153.Chemical Analysis SiO2 99.31% Al2O3 0.33% Fe2O3 0.028% MgO 0.04% CaO 0.09%4.Physical ...