A new report says the collapse in rough diamond prices has prompted the world’s largest producer to implement broad price cuts. Bloomberg reports that De Beers’ final sale of rough diamond stones on the secondary market was led by a 10% to 15% price cut amid a slumping market pressured by the proliferation of artificial diamonds and sliding demand across the West and China. Yet on Monday, the company capitulated on that position at its final sale of the year. De Beers cut prices by 10% to 15% for most of the goods it sells, according…