Standards are being developed at the International Organization for Standardization (ISO) to control the quality of batches of small diamonds to protect consumer interests.

High quality small diamonds, many of 0.2 carats and less, are widely used in the Swiss watch industry.

“We want to maintain the confidence in our product,” Dominique Dubugnon, Special Project Manager, Product & Process Improvement, Standardization, Swatch Group Quality Management, said in a panel discussion on the first day of the CIBJO Congress in Jaipur, India.

“All of you know that the Swiss watch industry is high quality, so we need to be sure that the customer has information on the product line.”

In September 2020, the International Organisation for Standardisation (ISO) published International Standard 24016, specifying the terminology, classification and the methods to be used for the grading and description of single unmounted polished diamonds over 0.25 carats in weight. Jean-Pierre Chalain, a panellist in the session and Vice President of CIBJO’s Diamond Commission, was convenor of TC174 Working Group 2 that oversaw the project.

More recently, work began on International Standard 24016, which would focus on quality control of diamonds of 0.25 carats and less. Once more, CIBJO’s Diamond Commission Vice President was appointed the convenor of the working group overseeing the project.

Already in 2015, the Federation of the Swiss Watch Industry FH had voiced its need for an ISO standard for harmonizing the quality control of small diamonds. 

The still-to-be-approved Standard 6893 will deviate from International Standard 24016 in that it will describe under which conditions the quality control of batches of small diamonds can be performed. It will provide recommendations using a statistical tool, known as Acceptable Quality Level, which will enable laboratories to perform the quality control of large quantities of small diamonds – including parcels of 500, 2,000 and even more than 50,000 diamonds – based on random samplings.

Patrick Loetscher, Head of Watch Industry Standards Department at the Federation of the Swiss Watch Industry, said, “Consumers should know what they are buying.”

Jonathan Jodry, Chair, ISO Technical Committee 174, ISO, said that if different checks were applied to a batch of diamonds, it would be very difficult to have a standard.

“It (standard) will give a single tool. The standards are not mandatory.”

Mr. Chalainsaid development of the new standards would create more work for diamond laboratories.

Tom Moses, GIA Executive Vice President, said he agreed with efforts to develop the standard.

“I fully agree with this initiative. More than 90 percent of polished diamonds weigh less than one tenth of a carat.”

The panel was chaired by Edward Johnson, Corporate Social Responsibility Director at Gemfields and a veteran gemmologist.