Another important change can be traced to the 1960s and 1970s, when some producers and dealers began testing the possibility of selling rough diamonds through alternative channels instead of the traditional practice of selling through the unified sales channel of De Beers’ CSO (). In the 1990s major producers began breaking away from the CSO (later transformed into the Diamond Trading Company, or DTC) to start selling their diamonds independently on the global market. At the same time producers began to channel an increasing amount of rough diamonds through auctions and spot sales that entail immediate payment and delivery
