Laboratory Manual Harmonization Committee (LMHC)
Information Sheets

The LMHC consists of seven of the world's major laboratories. They include the AGTA Gemological Testing Center (USA), CISGEM (Milan), GAAJ (Japan), GIA (USA), GIT (Thailand), Gübelin Gem Lab (Switzerland) and SSEF (Switzerland). For several years now, representatives of these laboratories have met to discuss the harmonization of identification procedures and wording on gemstone reports.
     To date, the LMHC has issued the following harmonization documents:

Document Date
Information Sheet 1 – Flux-healed corundum 03/24/04
Information Sheet 2 – Lattice-diffused corundum 01/27/04
Information Sheet 3 – Glass-filled corundum Updated Jan. 2006
Information Sheet 4 – Padparadscha sapphire Implemented Jan. 2006

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