Anglo American writes down value of diamond firm De Beers by $2.9bn

The world's biggest diamond miner De Beers cost its parent company almost $3bn last year as the growth in lab-grown stones continues to take the shine off the industry. Anglo American was forced to write down the value of the renowned gem producer for a second consecutive year as its chief executive admitted that the diamond markets had proved "really, really difficult for the company". Duncan Wanblad, the chief executive of the FTSE 100 miner, added that its plan to shrug off De Beers as part of a radical strategy to dismantle parts of the 108-year-old group - which coined…