The substance used to make glass is silica, primarily found in the form of sand. Glass is composed mainly of silicon dioxide (SiO2), and when heated to high temperatures, silica melts and can be shaped into various forms. The production of glass typically involves mixing silica with other materials, such as soda ash and limestone, which lower the melting point and improve the glass's durability and workability. Additional compounds can be added to create colored or specialized glass types. The versatility of glass in applications ranging from windows to containers underscores its significance in everyday life and industrial use.