Moti Ganz, President of the International Diamond Manufacturers Association (IDMA) has applauded Gareth Penny’s leadership as chief executive officer (CEO) of De Beers, in driving the company’s H1 results to stellar growth this year. Ganz said, "De Beers CEO Gareth Penny could not have created a more spectacular exit for himself: stepping down after reporting the highest H1 profits (EBITDA $762 million) in the history of De Beers (in relation to sales volume), and the highest return on assets ever achieved".

On the 84 percent increase in Diamond Trading Company's rough diamond sale in H1’10, Ganz said “Penny has fine-tuned sales to the needs of the manufacturing community.” He simultaneously cautioned that many manufacturers are creating polished needed for restocking among jewellers and retailers and consumer demand recovery is still fragile.

IDMA also concurred with De Beers Chairman Nicky Oppenheimer's sentiments that Penny was a “passionate and effective leader”.

IDMA Secretary-General Ronnie VanderLinden appreciated Penny’s conviction in reducing production by 50 percent and costs by 45 percent, maintaining commercial restraints, and not resorting to distress selling to reduce debts during the economic slowdown.