Diamond is pure crystallised carbon. Billions of years ago this carbon was crystallized deep in the earth by great pressure and heat. Diamonds were first found in India, about 2,500 years ago. The first diamond discovery in South Africa was only at the end of the 19th century. The main countries who are currently mining diamonds are Australia, Zaire, Botswana and Russia. France is in fifth place. It is usually found as octaëder crystals. Although diamond production has increased in recent years, it is estimated that in the course of history only a total of 500 tonnes of diamonds have been recovered from the ground. Only 15 to 20 percent of the diamonds that are found are suitable for processing into a piece of jewellery. Despite all modern technology, the mining of diamonds is still very complicated. Next to its rarity, the limited usability determines the high value of the diamond. On average just over six tons of raw stones are processed to win one gram of rough diamonds. The cutting of the diamond creates the unique, attractive sparkle. Diamond is the hardest gemstone (hardness 10) created by nature itself. The value of a diamond is determined by four factors; the four C's.
There are several forms in which a diamond can be cut. The most famous form is the brilliant cutting: the brilliant is round and the stone has 57 facets. The stones are cut so that the brilliance is optimal. There are many other possibilities. Common cuts are: brilliant, oval, square, princess, navette and baguette.
2. Carat, the weight
The weight of a gemstone is expressed in carats. The name carat comes from "Ceratonia Siliqua," which is Greek for carob. The seeds in the fruit of this tree weigh 200 milligrams and were used as weights. One carat is 200 milligrams, so there is 5 carats in a gram. A carat is divided into 100 points. For example, a stone of 10 dots is 0.10 carats.
Diamonds are found in a variety of colours, from pale yellow to canary yellow, light blue, green, pink and red. Naturally coloured diamonds are very rare and also very expensive since the late 20th century. Most diamonds are colourless, which are also known as white diamonds. This 'white' diamond can have different shades. These shades are internationally defined and used by the various laboratories for certifying diamonds.
During the crystallisation process of a diamond, if other minerals are near the stone (diamond) to be, these particles could get enclosed into the stone during the crystallisation. These particles or unclarities could be stones like garnet, but could also be already crystallised diamond crystals. This will be referred to as inclusions. The amount of inclusions in a diamond determine the purity of the stone.