Glass is primarily made from silica, which is a compound of silicon and oxygen found in sand. Other materials such as soda ash (sodium carbonate) and limestone may also be added to lower the melting point and improve the glass's durability. The silica is heated at high temperatures until it melts, allowing it to be molded into various shapes. The elements combined contribute not only to the structural integrity of the glass but also to its clarity and color, making glass a versatile material for a wide range of applications, from windows to art.