Gareth Penny got the wish of a lifetime when he landed the job of managing director of De Beers earlier this year. But the 44-year-old South African may have got more than he bargained for.

He was no surprise choice as head of the world’s largest diamond producer, having long been groomed for the top job. But even he may have been taken aback by the scale of the challenges he has faced since he took over on March 1.