Glass

Glass is a hard material that can be made in many shapes. It is usually transparent, but it can also be made in colours. Glass is made of sand that is heated until it is liquid. When it is liquid, it is shaped and left to cool.

Glass is often used to make windows and bottles. Many churches have windows made of colored glass.

The word "glass" can also refer to a drink container. It does not have to be made of glass, but can be made of any material, for example plastic.

Glass is used to make lenses. The word "glasses" is often used to mean eyeglasses.

The myth that glass is actually a liquid comes from the fact that old windows in houses and churches (2-300 years old) are sometimes a little out of shape: thicker at the bottom than the top. This is actually due to the process of glass making in the past which led to the glass pane being thicker at one edge than the other. It was sensible to install the windows with the thick edge at the bottom. Sometimes a window can be found with the thick edge at the top of the window.

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  Roman Glass Beaker from the 4th Century A.D.

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  A glass with water.

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  A glass ball with coloured shapes in it.

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  Stained glass windows in a Christian church.

Other websites

• Corning Museum of Glass
• A comprehensive guide to art glass and crystal around the world
• Working Description Furnace & Moleria - Murano Glass
• Informative website about the glass industry
• Substances used in the Making of Colored Glass
• Almost 400 articles and images about glass (mostly art glass)