The latest Congress took place from 4-7 September in Vicenza (Italy), where CIBJO launched the Opal Guide as part of the proceedings.
Featuring significant contributions from opal experts across Australia, the 186-page guide has been launched after 60 iterations. This guide is a complete classification of opal varieties from around the world, including primary commercial sources in Australia, Ethiopia, Mexico, and Brazil.
The CIBJO Opal Guide was conceptualised by the late Andrew Cody, who presented to the Coloured Stone Commission in 2016 on the need for a comprehensive guide for Australia's national gemstone. Following these calls, a draft was presented to a Congress in Bangkok in 2017.
CIBJO supported the idea, acknowledging the need for standardised nomenclature for opal, which was widely considered insufficiently understood and lacking global standardisation. In 2024, they agreed to produce a formal guide - and now, around nine years after the campaign began, the CIBJO Opal Guide is now widely available.
Among those representing Australia on the Opal Guide Working Group were: Ruth Benjamin-Thomas (Black Opal Direct), Damien Cody (Cody Opals), Terry Coldham (Intogems), Katherine Kovas (Gemmological Association of Australia), along with gemmologists Anthony Smallwood and Jenni Brammall, and geologist Kurt Steffens.
As the current president of the Australian Opal Association, Benjamin-Thomas said the commercial ramifications of standardising opal were enormous and thanked several key figures at CIBJO for their support, including Gaetano Cavalieri, Roland Naftule, Ken Scarratt, and Charles Abouchar.
CIBJO Opal Guide Working Group
 | Ruth Benjamin-Thomas
Black Opal Direct |  | Damien Cody
Cody Opals |
 | Terry Coldham
Intogems |  | Katherine Kovas
GAA representative, K&K Gems |
 | Anthony Smallwood
Gemmologist and valuer |  | Kurt Steffens
Geologist and boulder opal miner |
 | Jenni Brammall
Gemmologist and palaeontologist | |
Official CIBJO Opal Guide
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