De Beers, SA is a 125-year-old South African diamond company that has dominated the industry for decades. It's no secret that De Beers has long bought up and held onto lower-priced supplies of diamonds around the world in order to prop up prices for the gems. Its reputation was of a big, monopolistic power of the nastiest sort: maintaining warehouses to withhold diamonds from the market to prop up prices and increase the appearance of scarcity, rough handling of suppliers, a controlling force on what tends to be an insular industry.

In some ways, you've got to tip your hat to them: It wasn't always that a diamond was de rigeur for engagement rings, but De Beers' tireless advertising and promotion has propelled the diamond into a class by itself among precious gems. And De Beers -- 45% owned by Anglo American, PLC (NASDAQ:AAUK) -- certainly rules the roost in the ice business.

My colleague Dayana Yochim told me a funny story of interviewing De Beers executives in Toronto, as they would be subject to arrest if they set foot in the United States. De Beers has been blocked from operating directly in the U.S. since the end of World War II, stemming from an antitrust suit over the provision of industrial diamonds during the war. That case remains open; however, the Justice Department has no plans to continue the pursuit. This, the more important case for De Beers, responds to criminal charges filed against De Beers and General Electric (NYSE:GE) to fix the price of industrial diamonds. GE was acquitted in 1994, and De Beers never showed up for the trial, hid evidence, and basically gave the American justice system the finger.

De Beers has spent the last several years working on cleaning up its image. But one of the largest diamond merchants in the world, Tiffany & Co. (NYSE:TIF), has made substantial progress in procuring its own diamonds through its joint project with (and 14% ownership in) Aber Diamond (NASDAQ:ABER) and Rio Tinto (NYSE:RTP) in Canada. Aber, of course, has also made moves to wrest some of the sales channel away from De Beers, acquiring 51% of Harry Winston. These companies and others have sought to break the stranglehold De Beers has held on diamond supply, and they're achieving some success. Still, De Beers controls more than two-thirds of the global uncut diamond market.

De Beers isn't idle in the face of competitive pressures. It recently entered into joint-venture stores with LVMH in London and Tokyo, with another planned for later this year right in Tiffany's backyard on Fifth Avenue in New York. With this criminal case resolved, De Beers is free to pursue American business directly rather than through intermediaries. America remains the world's largest diamond market. All of this, a decade and more of problems, solved over a lousy $10 million. In the diamond industry, it should be noted that there are single stones that are valued at more than this.

A De Beers spokeswoman in Toronto noted that the company simply wants a clean slate. That's good business, and in a company with more than $5.5 billion in sales in the last year, the cost to do so simply wasn't very high.

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Bill Mann does not own shares of any company mentioned in this story.