The Laboratory Manual Harmonisation Committee (LMHC) is comprised of representatives from various gemmological laboratories located in Europe, USA and Asia.

The LMHC draws on the individual experiences of its members for the purpose of creating a general philosophy for proper nomenclature and disclosure for laboratories as well as to initiate and suggest "preferable" language to be used in the trade.

The goal of the LMHC is to achieve the harmonisation of gemmological report language and thereafter the revision of this harmonised report language as used by LMHC members.