(IDEX Online) - The G7 nations are today due to consider four options to implement a ban on Russian diamonds.They will discuss the technicalities and legalities of preventing goods, primarily from Alrosa, entering the supply chain.Belgium, India, France and the World Diamond Council have all put forward proposals.Belgium wants mandatory third-party blockchain technology to certify the provenance of all polished diamonds above 1.0-ct and all rough over 1.4-ct. There would be a single entry point for all G7 diamonds, likely to be Antwerp.India says its manufacturers should register with the government for exports of +1.0-ct goods to G7 countries, under a self-regulating system without blockchain or other tracing technology. An industry group in France proposes that sellers declare the origin of round, white +1.0-ct polished stones. There would be annual, independent audits but no blockchain and no provision for diamonds of other shapes or colors.And the World Diamond Council wants a self-regulated ban, with spot checks, on +1.0-ct goods, with sellers declaring they were not Russian, and setting up mechanisms to segregate them from non-Russian stones.The G7 countries - Canada, France, Germany, Italy, Japan, UK, US (and the EU) account for 70 per cent of global diamond sales.They are widely expected to announce sanctions to take effect on 1 January 2024.The US imposed sanctions on Alrosa shortly after Russia invaded Ukraine last February, but it did not cover goods cut and polished overseas and had no discernible impact on sales.Pic of rough sorting, courtesy Alrosa