Neatorama: '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.'