The art and science of making glass has been around for over 5000 years. This first glass was made by the ancient Egyptians and the city states of Mesopotamia. Glass is made from sand mixed with soda ash and limestone that is melted to over 3000 degrees. Technically, glass is a liquid or an amorphous solid with a molecular structure that is transparent. The addition of chemicals, colorants and different heating and cooling manufacturing processes are used to create the different glass types listed below.