You've probably herd that glass is made from sand. This is mostly true. Silicone-based sand is combined with lime and soda ash. Then, this mixture is heated, and as it cools down, glass is formed. Of course, today's glass makers tend to add additional minerals to the mixture in order to change the characteristics of glass. Some of these compounds change the color of the glass. Others make the glass sturdier or more heat-resistant.
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