(IDEX Online) - Speculation is mounting that the G7 nations will finally announce sanctions on Russian diamonds in September, 19 months after the invasion of Ukraine.They could be implemented, backed by a traceability solution, next January, after the all-important holiday season, according to a New York Times report.Brad Brooks-Rubin, senior adviser in the Office of Sanctions Coordination in the U.S. State Department, said G7 consumers accounted for almost 70 per cent of all diamond purchases.But sanctions will likely apply only to diamonds of one carat or more, he said. Much of Russia's diamond production is smaller stones, that wouldn't be covered.The US responded to the war in Ukraine last February with immediate, but largely ineffective, restrictions on sales of Russian diamonds. India and Dubai have not imposed any restrictions.Alrosa, Russia's state-controlled diamond miner, reported first-half sales of $1.9 bn earlier this month, a slight increase on its pre-war revenue.The G7 nations - Canada, France, Germany, Italy, Japan, the United Kingdom, the US (and the EU) - met in Hiroshima, Japan, in May, when they deferred a decision on sanctioning Russian diamonds.Pic of rough sorting, courtesy Alrosa