What is glass made of?
Q: What is glass made of?
A: Glass is mainly composed of silica, and specifically soda-lime glass is made up of silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, also called lime (CaO), and several minor additives.
Q: How can different colours be added to glass?
A: Different colours can be added to glass by adding small amounts of metal oxides. For example, a blue colour is given by tiny amounts of cobalt oxide.
Q: What does the term 'cut glass' refer to?
A: Cut glass refers to glass that has been decorated entirely by hand using rotating wheels which make cuts in an otherwise smooth surface.
Q: Where did the myth that glass is a liquid come from?
A: The myth that glass is actually a liquid comes from the fact that old windows in houses and churches (200–300 years old) are sometimes a little out of shape due to the process of making them in the past which led to them being thicker at one edge than the other.
Q: What are glasses often used for?
A: Because glass is used to make lenses, "glasses" often refers to eyeglasses or spectacles.
Q: Is crystal actually a crystal?
A: No, crystal glass is not actually a crystal because all types of glass are non-crystalline solids.
Q: Can recycled materials be used when making new pieces of glass? A: Yes, recycled materials such as bottles and jars can easily be recycled into new pieces of glasses or used in industry as aggregate or sand.
