The document discusses De Beers and the global diamond industry. It describes how De Beers established a monopoly by controlling diamond mining and sales. It controlled around 80% of the market at its peak in the 1920s and still controls around 40% today. It discusses how De Beers works to control supply and prices through stockpiling diamonds and restricting sales. The document also provides background on major diamond producers, how the diamond trade works, and competitors that have challenged De Beers' dominance like Lev Leviev and Rio Tinto.