(IDEX Online) - Sanctions on Russian diamonds could force jewelers to amend their designs, say De Beers boss Bruce Cleaver, as they struggle to source enough melee.Alrosa, part-owned by the Russian government, produces a disproportionate percentage of the world's stones under 0.2-cts (the GIA's definition of melee).As a result, designers may have to find other ways to accentuate the large, central stone on a ring or other item of jewelry."We produce very little of that and the Russians produce a fair amount of that," Cleaver, CEO of De Beers Group, told The Times of London. "That will ultimately be a potential challenge for retailers who use a lot of melee."Alrosa produces a large portion of the supply of melee and even smaller stars (0.009 and 0.021 carats)."Diamond jewellery designs are not set in stone. Jewellery designers are very innovative and very good at working with what they've got," said Cleaver.Pic courtesy GIA