To the southeast of the teeming herds of wildlife in the Okavango Delta in Botswana, an offshoot of the Lundin mining dynasty is extending its search for the world’s biggest diamonds. Lucara Diamond Corp is sinking an 800 m shaft to ensure the kimberlite orebodies at its Karowe mine keep producing the 1 000-ct-plus gems that set it apart. However, the $550-million investment is potentially less significant than the second prong of the miner’s strategy.