Container glass is a vitreous silicate, the primary ingredients of which are silica sand (SiO2), calcium carbonate (CaCO3), and soda ash (Na2O). Although silica has a melting point of over 3000¬?F, in the presence of the other fluxing and fining agents, the sand forms a glass at temperatures below 2500¬?F. With proper cooling, the silicate remains a glass at room temperatures. Most clays are silicates, as well.
