Glass is amorphous inorganic non-metallic materials, generally with a variety of inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda ash, etc.) as the main raw material, plus a small amount of auxiliary raw materials of. Its main ingredients are silica and other oxides. Ordinary glass chemical composition is Na2SiO3, CaSiO3, SiO2 or Na2O CaO 6SiO2, the main component is the double salt of silicate, is a random structure of amorphous solids. Widely used in buildings, used to wind and light, belong to the mixture. In addition, some colored glass colored with oxides or salts of some metals and toughened glass prepared by physical or chemical methods are also included. Sometimes transparent plastic (such as polymethyl methacrylate) is also called plexiglass.