Gemmological Commission reveals results of survey of gem labs, looking at how they differentiate reporting of natural, synthetic and treated diamonds

October 16, 2018

The meeting of the Gemmological Commission opened with the body’s President, Hanco Zwaan, discussing a survey conducted prior to the CIBJO Congress with gemmological laboratories around the world, on how they report on natural, synthetic diamonds and treated diamonds.

Overall, he said, the nomenclature used is clear about the nature of the stones described, but there were some inconsistencies in precise terms used, and whether or not synthetic and treated stones are actually graded. The results of the survey were reported back to the board for further discussion.

Some of these terms and grading principles are not in accordance with the rules in the CIBJO diamond Blue Book, he said.

The next issue on the agenda was the current status of an informative document covering colour terms. Mr. Zwaan showed a preliminary draft, which includes terms used to describe certain colours of ruby and sapphire. Information has been added since last year and the document now reflects the positions of a number of important labs.

The document includes an attempt to show where the respective colours approximately lie, referring to the Munsell colour charts. Because a universal standard is lacking, it is hoped that a modified draft will increase transparency on this subject in the sector.

The meeting then discussed the issue of the separation of facts and opinions on lab reports. The Coloured Stone Commission asked the Gemmological Commission whether it is possible to separate test results from professional opinions of lab reports. It was agreed that ultimately reports need to be done in this way, so as to make them more understandable to consumers.

Shane McClure of the Gemological Institute of America noted that GIA and other labs state on their reports that specific results given on the reports, such as origin, are opinions. Charles Abouchar suggested that labs should use terms like “GIA-type Burma” or SSEF-type pigeon blood” to state clearly that both origin and colour terms are an opinion and not a fact.

Meanwhile, Nilam Alawdeen argued that consumers believe that the results given on a lab report are based on industry standards which is not, in fact, the case. To clarify this, it should be clearly mentioned that some information given on a report are opinions, which would also protect the lab itself.

On the issue of variety names, Mr. Zwaan said that he had informed the Gemmological Commission Steering Committee that a working group is being formed of members of the Coloured Stone and Gemmological Commissions, to propose a list of accepted variety names. It would also attempt to give as precise definition of the variety names as possible.

By |2018-10-18T16:42:17+00:00October 18th, 2018|NEWS|Comments Off on Gemmological Commission reveals results of survey of gem labs, looking at how they differentiate reporting of natural, synthetic and treated diamonds
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