29 Nov LMHC makes progress on harmonisation of colour description and new treatment issues
Significant achievements in the harmonisation of wording on laboratory reports and the reporting of new treatments have been chalked up during the 29th meeting of the Laboratory Manual Harmonisation Committee (LMHC), which was hosted by the Gübelin Gem Lab in
Lucerne, Switzerland, on November 14 and 15, 2018.
The LMHC is currently comprised of representatives from the Central Gem Laboratory (CGL), CISGEM Laboratory, DSEF German Gem Lab, Gübelin Gem Lab, GIA Gem Laboratory, the Gem and Jewelry Institute of Thailand (GIT) and the Swiss Gemmological Institute SSEF. The organisation is not formally connected to any trade organisation.
During the meeting, the LMHC members agreed to modify infosheet No. 4, concerning the use of the term “padparadscha.” The infosheet now specifies that the term is not applicable if the colour of the stone is unstable and shifts to pink when exposed to a colour stability test (see Figure 1). Additionally, a new infosheet about organic fissure-filling in any gemstone (IS No. 12) and an infosheet about hydrophane opal (IS No. 13) were unanimously approved by the laboratory representatives.
The press release of the LMHC meeting can be downloaded here.
Link to new LMHC website.