The CIBJO Gemmological Commission has released a Special Report outlining some of the issues related to nomenclature and identification that it proposes to discuss at the CIBJO Congress to be held in Brazilon May 4, 2015. The report, authored by Commission head Hanco Zwaan says that the issues are important as they contribute to alleged inconsistencies in the results reported by different laboratories.

The Commission contends that while the laboratories may differ in their approaches and opinions on the wording used on reports, there is a need for achieving harmonisation of methods and nomenclature. It points out that the CIBJO Blue Books and the sheets produced by the Laboratory Manual Harmonization Committee (LMHC) have already done work in this direction.

Zwaan mentions the discussions on opal and hydrophane treatments which took place at the Moscow Congress, and how the Commission is working with the LMHC to finalise a sheet recommending how hydrophane should be reported.

Other issues that will be discussed include:

• Standardization and communication of ruby and sapphire colours
• Formulation of standard usage of commercial terms (eg colour descriptive terms such as ‘pigeon blood red’ and ‘royal blue’) on gemmological reports
• Clarifications regarding the name ‘Organic Ruby’ being used to decribe lead-glass filled ruby that are surface-only lead-free products
• The tanzanite nomenclature in the blue book
• Concerns raised by enhancement of emeralds, applied after certification

A short update will be given on the progress LMHC has made on further harmonising laboratory nomenclature, the Report said in conclusion.

Photo caption: 'Improved' lead glass-filled rubies, marketed under the name 'Organic Ruby', (Courtesy: Netherlands Gemmological Laboratory)