Wall Street JournalTiny Company Hits King-Size Diamond JackpotWall Street JournalLONDON—When a tiny Canadian company bought a majority stake in an unloved Botswana diamond mine in 2009, almost no one noticed. Seven years later, the Karowe mine is the world's biggest producer of large diamonds, and the company, Lucara ...Botswana's Big Diamond Is Up For Auction Today.