De Beers mines diamonds, then handle their sales and distribution through various entities (in London, it's known as the innocuously named Diamond Trading Company; in Israel, it's simply called "the syndicate"; in Belgium, it's called the CSO or Central Selling Organization.) If you want to buy diamonds from De Beers, you've got to play by their rules: diamond are sold in events known as "sights." There are 10 sights held each year, and to buy, you have to be a sightholder (these are usually diamond dealers whose business is to have the stones cut and polished and then resold at diamond clearing centers of Antwerp, New York, and Tel Aviv). The diamonds are sold on a take-it-or-leave-it basis. A sightholder is given a small box of uncut diamonds priced between $1 and $25 million. De Beers set the price - there is no haggling and no re-selling of diamonds in uncut form. It is rare for sightholders to refuse a diamond package offered to them, for fear of not being invited back. And those who dare to purchase diamonds from other sources than De Beers will have their sightholder privilege revoked. In the early days, De Beers controlled about 90% of the world's diamond supply. Today, its monopoly on diamonds has been significantly reduced. It is estimated that the cartel now controls about 60 to 75% of the world's diamond trade

One of DeBeers. main roles is to maintain the notion that diamonds are a scarce commodity. This they do by means of advertising and by purchasing excess supplies when that is needed to avoid price decreases: as a matter of principle, prices are never lowered by DeBeers. This tightly-knit organization has proven beneficial for most in different ways: producers, often state-run diamond mines in developing countries relying heavily on diamonds, are provided with a stable inflow of foreign currency. Dealers enjoy stable price increases which can easily be passed on to consumers. DeBeers, however, seems to be benefiting the most from the agreement, asking for what producers often perceive as inappropriately large fees and in turn charging prices to merchants at their own discretion.

Some books to read about the terrors of diamonds: