De Beers says it will reduce its production to extend the life of its mines. Taking into account the moderated output diamond prices could rise by at least 5 per cent a year for the next five years, according to Des Kilalea, a diamond analyst at RBC Capital Markets. In 2008 De Beers produced 48m carats and the company will cut production to 40m in 2011. In the last two decades the industry has found no new diamond deposit to match the two biggest mines in Africa, owned by De Beers, or the best Russian mines of Alrosa, the other...