Soda-lime silica glass combines three essential ingredients. Silica (sand) is the glass forming oxide, lime provides chemical stability and soda ash acts as the fluxing agent. Soda ash plays a vital role by reducing the furnace temperature necessary to melt the silica used, thus reducing the energy required to produce glass. As a cost-effective source of Na2O, it also usually supplies the bulk of the alkali element needed in glass making.