As the diamond industry battled with a dramatic fall in demand in recent months, no one has been closer to the front line than Sheila Khama, chief executive of De Beers in Botswana.

“Events have been to say the least extraordinary,” says Ms Khama, the 52-year -old who has spent most of the last decade-and-a-half at De Beers, the world’s largest diamond company. “There has been nothing normal about this year. Every quarter there has been a new revelation. The worst [has been] driven by the uncertainty.”