The diamond is the hardest known substance in the world. It can cut through steel by pressure alone. Incredibly, the diamond is the only gemstone made of just one element -- carbon, the building block found in every living animal and plant.
Part of the mystery of the diamond is that it gets formed at all. Billions of years ago, in a deep layer of the earth, a unique combination of chemicals, pressure, and temperature changes created diamonds out of pure carbon. This was no easy task -- the pressure needed to create a diamond is close to what you’d get if you balanced a skyscraper on a small, flat metal disk.
Violent and powerful volcanic eruptions forced cone shaped veins of diamond-bearing ore – called Kimberlite -- to the earth’s surface, where they can now be mined. Mining techniques can process thousands of tons of diamond ore a day, but it still takes 250 tons of ore to produce one carat of rough diamond. Of all retrieved diamonds, only 20% are gem quality stones.