CIBJO releases Gemmological Report
CIBJO Gemmological Commission Special Report surveys Gem labs about synthetic and treated diamond reports With fewer than four weeks to go to the opening of the 2018 CIBJO Congress in Bogotá, Colombia, on October 15, 2018, the sixth of the CIBJO commissions' Special Reports has been released. Prepared by the CIBJO Gemmological Commission, headed by Hanco Zwaan, it reveals the results of a survey of 23 gemmological laboratories from around the world, about whether and how they report on synthetic and treated diamonds. "The survey provided a clear picture of the similarities and differences on the reports issued by the various laboratories, and perhaps also suggested the requirements and preferences of different markets around the globe," wrote Mr. Zwaan. "Overall the nomenclature used by laboratories is clear about the nature of the stones described, but there are inconsistencies with regard to the precise terms used, and whether or not grading of