13-12-2018
Term harmonisation of laboratory reports is reached during the Laboratory Manual Harmonisation Committee (LMHC) meeting hosted by the Gübelin Gem Lab in Switzerland. The committee comprises representatives from Japan’s Central Gem Laboratory, the Swiss-based Gübelin Gem Lab, the Gemological Institute of America (GIA), the Gem and Jewelry Institute of Thailand, and the Swiss Gemmological Institute.
Attendees agreed to modify the use of ‘padparadscha’ to ‘not applicable if the colour of the stone is unstable and shifts to pink when exposed to a colour stability test’ (photo 1), which means only stones which have stable colour are qualified as padparadscha sapphires. Chief gemologist at Gübelin Gem Lab and co-chair of LMHC commented a harmonised colour description is important for trade and consumers.
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