Weight, Cut, Color, Purity, Proportions ...

The diamond is the hardest gem in the world, and the most simple in composition: it is pure carbon. Billions of years ago, due to temperatures around 1200°C and extremely high atmospheric pressure of 10,000 atmospheres, carbon crystallized deep in the earth. When volcanoes erupt, diamantiferous magma rises higher to the earth's surface. The first mining operations started 500 B.C., in India. Today, the biggest mines are based in South Africa, and more recently in Russia. To obtain a 1-carat diamond, miners have to extract approximately 250 tons of ore. Only 20 % of rough diamonds are used for jewelry. The remaining 80 % are used in industry. This means that just for a 1-carat solitaire, there is more 1250 tons of ore extracted.