The diamond is a jewel known and precious in the world because it is extremely rare. Natural diamond can be found on its host rock, which is kimberlite and lamprolite (Bulanova 1995, 2). However, the percentage of diamonds is small. For example, only 5 grams of diamond can be obtained from 10 tons of host stone (Rigby 1991, 118). It takes its name from a Greek word, Adamas, meaning indestructibility (O'Donoghue 1993, 104). Diamond is the hardest known mineral having the highest value 10 on the Mohs hardness scale. Diamonds are often obtained in transparent form, where blue, light green, pink, purple, and reddish diamonds are extremely rare (Cipriani and Borelli 1986, 74). Many people think that diamonds are formed from the metamorphism of coal. However this is not the case. One of the processes of natural diamond formation occurs in the soil deep beneath the Earth's crust in the mantle. Diamonds are made up exclusively of carbon atom. Diamonds form naturally at extremely high temperatures and pressures by forcing together the molecular structure of the carbon atom. However, if the temperature and pressure are different from the diamond condition, graphite, which is a chemically identical allotrope to diamond, will form with completely different characteristics. Successfully formed diamonds will be deposited in the diamond stability zone beneath the continental crust. Then the diamonds are transferred to the earth's surface via a volcanic eruption. The blue-bottom and yellow-bottom volcanic tubes with cylindrical shape that transfer diamond to the surface are called Kimberlite by H.C.Lewis (Erlich and Hausel 2003, 79). On the other hand, natural diamond is not only formed deep underground, it can also form in the middle of paper......on the earth's surface, so high velocity, temperature and pressure are produced at this point (Chapman and Morrison 1994). Temperature and pressure are the best conditions for diamond formation, so small diamonds are found near the collision site. The asteroid crashes into graphite at a certain temperature and pressure, thus forming diamonds (Gizmodo 2012). The diamonds found are called impact diamonds, not suitable for making jewelry, but can be used for industrial purposes, proposed by IDEX (Gizmodo 2012). Diamonds formed by different methods, which are formed under the crust and transported to the surface via kimberlite tube, formed in space, subduction of oceanic crust and asteroid impact. Only diamonds formed beneath the earth's crust can be used as jewelry where impact diamonds are used for commercial purposes.