With little more than seven weeks to go to the opening of the 2026 CIBJO Congress in Vicenza, Italy, on September 4, 2026, the fourth of the pre-congress Special Reports has been released. Prepared by the CIBJO Diamond Commission, headed by Udi Sheintal, the report focuses on several topics, but most predominantly on the proposal that the word “synthetic” be regarded as the preferred term to describe diamonds created through industrial processes, and that the 4C grading system be exclusively used with natural diamonds.

“The Diamond Commission should continue to explore every way possible to restrict the use of the 4Cs so that they refer only to natural diamonds,” writes Mr. Sheintal. “This is because it is a tool intended to define the rarity and uniqueness of natural stones, where each one is different from the other. We need to end the use of the 4Cs for grading synthetic diamonds, given that they are industrially produced. They should be subject to a specific quality-control nomenclature, which is suitable for man-made products.”

“When the 4Cs grading scale is used by the synthetic diamond industry to describe its production, the consumer is misled to believe that synthetic diamonds are rare like natural diamonds. This is clearly not the case, because the synthetic diamond manufacturer determines and controls the production parameters, with the objective of achieving predetermined quality characteristics,” Mr. Sheintal adds.

“Standards exist precisely because industries evolve”, Mr. Sheintal continues. “Therefore, the question before us is not whether synthetic diamonds should exist. They are legitimate products, manufactured through impressive technological innovation and serving legitimate consumer demand. Nor is the question whether manufacturers of synthetic diamonds should be entitled to market their products successfully. The question is considerably more fundamental. Do the words we use today continue to fulfil the purpose for which international nomenclature was originally created?”

In preparing the report, Mr. Sheintal invited other Diamond Commission members and industry officials to contribute, including Jean-Pierre Chalain, Diamond Commission Vice President; Thomas Lind, Vice President of CIBJO’s Sector A, which covers all gem materials; Peter Karakchiev, Head International Relations at ALROSA; and Alan Cohen, a member of the Diamond Commission.