Silicon dioxide is known as Silica , SiO2. 95 % of the earth crust is made up of silica and silicates.It occurs in several crystallographic forms , namely , quartz , cristobalite and tridymite.These crystalline forms are interconvertible at suitable temperature. Structure Silicon dioxide is covalent , three- dimensional network solid in which each silicon atom is … [Read more...] about Silicon Dioxide, Silica