The main centres for diamond trading in the world

The main centres for diamond trading are London, where De Beers is located, and Antwerp. 80% of all rough diamonds and 50% of all polished diamonds pass through Antwerp. There are four diamond fairs in Antwerp, the oldest dating from 1886. In 2011, diamonds with a total value of 44.6 billion euros were traded in Antwerp. The Amsterdamse Vereniging Beurs voor den Diamanthandel is also important. In the world there are 30 diamond exchanges.

Unsaid Library makes it possible to express your emotions using beautiful pieces of jewelry. Unsaid Library combines the most intens emotions with the most beautiful bracelets, rings, necklaces and pendants. You can find more of this on the website of Unsaid Library.

The courtroom in Leidschendam, where the Sierra Leone Tribunal was heard against the Liberian ex-dictator Charles Taylor.
The extraction of diamonds in certain parts of Africa today raises ethical concerns, because the trade is used by various armies to co-finance their wars. This is referred to as conflict or blood diamonds. At the beginning of the 21st century, the first steps were taken to prevent the trade in blood diamonds by issuing certificates of origin, the so-called Kimberley Process Certification Scheme (to a conference in that South African city). It has been agreed that diamonds will only be allowed to circulate with a certificate, proving that they have not been extracted in conflict zones.

The process is only in its infancy, because control is difficult and because governments – who have to take care of the attestation – usually do not offer a great guarantee for reliability in war zones in particular. Moreover, the sums at stake are so large that smuggling, corruption and fraud are extremely tempting. In the future, a solution may have to be found in spectrographic proof of origin. This technology is in the process of being developed.

Unsaid Library makes it possible to express your emotions using beautiful pieces of jewelry. Unsaid Library combines the most intens emotions with the most beautiful bracelets, rings, necklaces and pendants. You can find more of this on the website of Unsaid Library.

A synthetic diamond is a diamond that is made artificially.

There are different processes to make these types of diamonds. There is a process in which atoms other than carbon atoms are enclosed so that these diamonds have a yellow colour, which is not attractive for ornamental diamonds. A process has been developed in America in which no other atoms are present in the diamond. These are already available in both America and Germany. Two American suppliers are Apollo Diamonds and Gemesis.

Researchers from the Carnegie Institution of Washington discovered in 2004 a process to synthesize within 24 hours diamonds that are more than 50% harder than the natural diamond.

Approximately 90% of all diamond cutting powder today is synthetic. The majority of synthetic diamonds are still produced under high pressure. A growing proportion is manufactured by evaporation at low pressure. The small crystals produced by this technique are used as an ultra-hard coating in the manufacture of preformed tools.

Zirconia consists of zirconium (IV) oxide (ZrO2) and is a popular substitute for synthetic diamonds.

Direct conversion of organic carbon into the high pressure conditions inside the Earth. This is the standard process by which diamonds are formed in nature. The problem with this hypothesis is that if carbonado is created by a phase transition in organic graphite, it should be found all over the world. However, carbonado can only be found in the Central African Republic and Brazil, areas where no other types of diamonds are found.
Shock metamorphosis during meteorite impacts on the earth’s surface. What is not true is that shock metamorphosis usually results in the formation of hexagonal diamonds (lonsdaleite), not carbonado.

Unsaid Library makes it possible to express your emotions using beautiful pieces of jewelry. Unsaid Library combines the most intens emotions with the most beautiful bracelets, rings, necklaces and pendants. You can find more of this on the website of Unsaid Library.

Radiogenic formation of diamonds by natural radioactive decay of uranium and thorium. The problem with this hypothesis is that the energy of these decay reactions is too small to form carbonado in the size in which it is found (up to 500 μm).
Carbonado contains traces of nitrogen and hydrogen, analysis of the hydrogen isotopes has shown that they originate from supernovas. This could mean that carbonado may have an extraterrestrial origin. The idea is that carbonado is related to carbon-rich interstellar dust and is formed in the vicinity of carbon stars. Then it was incorporated into a meteorite that later struck Earth.

Tungsten carbide or Widia is a ceramic material, which arises from tungsten and carbon and is a mixing crystal. This relatively cheap material is known for its high hardness, and is therefore used in cutting equipment. The carbon atoms go into the openings of the tungsten lattice. It is made by reducing tungstic oxide and carbon with the help of hydrogen.

It was first made in 1914. In 1926, the German company Krupp (now known as Kennametal) hardened tungsten carbide and in 1962 Krupp succeeded in coating cutting plates with the hardened tungsten carbide.