CIBJO has been releasing a slew of Special Reports in the build-up towards the 2019 CIBJO Congress scheduled to take place in Manama, Bahrain, on November 18, 2019.

The latest, and seventh, Special Report recently  released, prepared by the CIBJO Gemmological Commission, headed by Hanco Zwaan, “considers measures that should be taken to ensure that a person reading a laboratory report understands what information is measurable fact and what information represents the opinion of the gemmologist”, the organisation said.

“Dividing the report so that there is a section with test results and a section with interpretations or opinions may cause even more confusion,” Zwaan writes. “The more prudent policy could well be what some laboratories already do, and that is clearly stating on their report that specific results – such as those dealing with origin—are in fact opinions.”

In the opinion of CIBJO’s Gemmological Commission, the practice of many gem labs to assign variety names to gemstones, despite there currently not being universally accepted gemmological standards for those names, is particularly controversial; and has been driven more by commercial interests rather than science. “The general attitude has been that, as long as new variety names were not in conflict with science, logic, or other, already given names, they could be accepted,” Zwaan notes.

He goes on to say: “Conflict with commercial interests are fraught with problems.” Zwaan cites the case of Paraiba tourmaline, which, he notes, most commonly is recognised by its distinctive colour, but some insist also needs to have been sourced in the Brazilian state of Paraiba. This means that similarly coloured tourmaline from Mozambique and Nigeria should not share the same variety name. “Does that make Paraiba tourmaline a variety or a brand?” he asks.

“What we do know is that, historically, once a brand or trading name becomes widely accepted in the public sphere, it is more likely to be used as a variety name,” the President of Gemmological Commission states in the special report. “This in itself is a compelling enough reason to define variety names precisely.”