CIBJO Gemmological Commission considering
amendments to gemstone variety definitions

The Gemmological Commission in session on October 5 (from left): Thanong Leelawatanasuk, commission Vice President, Hanco Zwaan, the commission’s President; and Claudio Milisenda, another of the commission Vice President.

OCTOBER 5, 2023

Reporting in its activities during the third day of the 2023 CIBJO Congress on October 5, Gemmological Commission detailed the operation of a working group it is leading to consider amendments to definitions of gemstone varietal names, which should reduce risks of inconsistencies by laboratories and help to protect consumer confidence.

The commission was chaired by Commission President Hanco Zwaan, supported by Vice Presidents Claudio Milisenda of the German Gem Lab and Thanong Leelawatanasuk of the Gem and Jewellery Institute of Thailand (GIT.)

The Commission is working on a gemmological book of amendments to more clearly define minerals and gemstones, incorporating 278 entries of different names, such as actinolite, agate, and so on.

“This list is to help with definition of names,” said Dr. Zwaan stated.

“Does a name refer to a mineral or a gem variety name or a trade name? For example, Fei Cui is designated as a trade name in the document.”

Dr. Zwaan added, “It could be that trade names today could become variety names after some time.”

He said, “This document is a baseline from which we can start discussions on borderline cases. The labs will later decide what to do with this information.”

Gemmologists have noted inconsistencies in lab reporting of gemstones, for example over a colour definition surrounding green beryl and emeralds, or the origin of sapphires.

Speaking from the audience, Wesley Hunt, Director, Programme Management, at De Beers Consumer & Brands, who also is Chair of the CIBJO Laboratory-Grown Diamond Committee, noted that laboratory grown diamonds are diamonds, but they are not gemstones because they are not minerals.

The ongoing research will aim to reduce risks of inconsistencies, enabling a more level playing field for lab reporting which in turn will help to underpin consumer confidence in gemstones set into jewellery.

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