Silicon dioxide , also known as silica (from the latin silex), is an oxide of silicon with the chemical formula SiO2, most commonly found in nature as quartz and invarious   living   organisms.   In   many   parts   of   the   world,   silica   is   the   major constituent of sand. Silica is one of the most complex and most abundant families of materials existing as a compound of several minerals and as synthetic product.Notable examples include fused quart, fumed silica, silica gel, aerogel. It is used in   structural   material,   microelectronics   and   as   components   in   the   food   and pharmaceutical industries (Todd etal, 2012)