Why does a diamond sparkle?

Diamonds were not as rare as they are, or take it as they didn't cost much and almost everyone could have them easily, would diamonds still be valuable? Two things would probably make people still want to have diamonds. One is that a diamond is the hardest substance ever known to man. So diamonds would still be very useful in industry. The second is that diamonds would still be beautiful and so people would still enjoy looking at them. Diamonds are the result of a process that took place in nature. Millions of years ago, the earth was gradually becoming cooler. At that time, there existed beneath the ground a mass of hot liquid rock. This mass was subjected to extreme heat and pressure. As a result of this, molecules of carbon became packed together in dense, clear crystals.

A diamond is simply a crystal of pure carbon. When a diamond is found in "rough" form its outside appearance is rather dull. Now man takes over to make it into the sparkling germ we all know about. Most diamonds are sawed in two, and each half is shaped and cut into a round diamond called a brilliant. The reason for this is that a diamond has a very high refractive power. This means that when light enters it, the diamond lends the light more than other substances do. The light, instead of passing through the diamond, is bent so that it is reflected back into the stone. So a greater amount of light is returned to our eyes when we look at a diamond and it looks more brilliant. The diamond also breaks up the light into its different color, which gives a diamond its fire. Did you know that diamonds were not worn as personal ornaments until 1430, when a Frenchwoman called Agenes Sorel started the custom. Thenceforth the custom spread.