Diamond
Diamonds are among the natural minerals with the highest hardness, and they are also called gem stone as a brilliant gem. It is one of the most representative jewels. However, in order for a diamond to have value as a gemstone, it must maintain a certain shape. Otherwise, it is used as industrial diamond. The main component is carbon and has very different properties from graphite, which is a natural product of the same atom due to differences in molecular structure. Because of its excellent hardness, it is widely used for industrial purposes, but most industrial diamonds use human-made artificial diamonds. At present, it is difficult to distinguish between poorly-quality natural diamonds and high-quality industrial diamonds. Often the unit of mass of a diamond is the carat used as the unit of mass of most gems. Diamonds are completely burned between 1400 and 1607 degrees F depending on their strength. In fact, the place where diamond is formed is under 130 kilometers below ground.