Can anyone save the world’s most important diamond company?

In February 1908 Joseph Asscher, a master cutter of diamonds, cleaved the Cullinan at his workshop in Amsterdam. So tough was the South African diamond, the largest ever found, that Mr Asscher’s first attempt split his blade instead. The diamond industry is once again gripped by a nail-biting separation. This time, its most important company is facing the chop.

After rejecting a takeover proposal from BHP, the world’s biggest miner, Anglo American announced a radical restructuring of its business on May 14th. As well as selling its coal, nickel and platinum operations, the British mining firm will shed its 85% stake in De Beers (Botswana, where its richest diamond mines are located, owns the rest). BHP has until May 29th to make a new offer for Anglo. Whatever happens, De Beers’s change of ownership marks the end of one of the company’s most enduring relationships—Ernest Oppenheimer, Anglo American’s founder, joined its board in 1926. For the industry, it signals the biggest shake-up since 2000, when De Beers abandoned its policy of controlling diamond prices by managing supply.