Diamonds in the Sky

Abstract

People of all ages and cultures have always been fascinated by diamonds, attracted by their beauty, glitter, and rarity (and therefore value). For over 2000 years, diamonds were found mainly in pebbles in riverbeds. The discovery of diamond-containing rocks in South Africa led to the realization of volcanic pipes as a source of diamonds. It is interesting to note that diamond is a form of pure carbon, the fourth most common chemical element of the Universe, after hydrogen, helium, and oxygen. The rarity of diamonds is therefore not due to its chemical composition, but the result of how and where they are made. The diamonds on Earth are believed to have formed under high temperature (~1,000 °C) and pressure (4,500 times the pressure we experience everyday under the Earth’s atmosphere) in the deep (100–300 km) interior of the Earth, and brought to the near surface by volcanic activities.