The gem, discovered a decade ago at one of De Beers mines in South Africa, is one of just five diamonds over 100 carats and of comparable quality to have been offered at an auction.
In this interview with The Mining Report, he shares his secret for finding companies that can create value despite challenging market conditions, and he reveals where he is putting his money today.
Global exploration spending dropped 26% in last year, compared with 2013, as several juniors threw in the towel and producing miners slammed the brakes on capital and exploration expenditure.
The Swiss Gemmological Institute (SSEF), one of the world's most respected gem research, education and grading institutions, has inaugurated a state-of-the-art laboratory in Basel, more than doubling the size of its previous facility and enabling a massive expansion of the services it has provided the gemstone, jewellery and watch industries for more than 40 years.