Glass
The very first glass was made when lightning struck sand -- like beach sand. The lightning heated the sand until it melted and the resulting material was glass in its most basic form, modern glass manufacturers mix sand with soda ash, limestone and CULLET, or recycled glass, to make glass containers. Soda ash is a white, powdery mineral which lowers the melting temperature of sand.
Limestone, another natural substance, increases the durability of the glass. These ingredients are heated to about 2700 degrees Fahrenheit until they melt into a soft liquid, or "molten," state. The hot molten glass is pressed and blown into molds where it forms bottles and jars. The new containers are cooled and checked carefully for any defects, like cracks or bubbles. Finally, they are shipped to companies where they are filled with foods and beverages.
Information from Glass Packaging Institute's web site at http://www.gpi.org and Owens-Illinois' web site at http://www.o-i.com.
