LONDON—When a tiny Canadian company bought a majority stake in an unloved Botswana diamond mine in 2009, almost no one noticed. Lucara, a company run by five... Seven years later, the Karowe mine is the world’s biggest producer of large diamonds, and the company, Lucara Diamond Corp., is the dominant player in the market for supersize gems.

Source: Wall Street Journal June 29, 2016 14:00 UTC