CGL Laboratory


Carat Gem Lab is an independent gemological laboratory established in France since 2009.

The laboratory provides a full range of services for trade members. Our activities are focused on three major axes, which are :

  • expertise
  • research
  • education


Gemological expertise consists in analyzing natural and synthetic diamonds and colored gemstones and to issue analysis reports. Each of those reports, which contains detailed funding obtained during the tests, are usually required for commercial transactions, as well as for insurance purposes.

The main categories of expertise documents that are provided by the laboratory are related to :

  • grading and identification of colorless diamonds
  • grading and identification of colored diamonds
  • identification of colored gemstones
  • origin determination of rubies, sapphires, emeralds and alexandrites
  • identification of jewelry


The gemological research activities that we are conducting allow the laboratory to keep his international level of knowledge and skill. For these reasons, we are involved in different research projects that we are conducting internally to the laboratory, and others that we are developing in collaboration with universities and other international research teams.

Once completed, the results of our research projects are regularly published in different gemological magazines and journals in Europe, North America and Asia. In addition to articles, research results are also presented to the trade and scientific community during congress and through our laboratory educational programs.


The Carat Gem Lab education programs are mainly dedicated to the trade members (jewelers, jewelry staff, dealers and gemologist) because they require some initial knowledge about gemstones. Each program works independently from the others and focuses on a special topic.

The courses are built on a workshop basis, including practical and theoretical parts. The purpose of each workshop that range from an intermediate to an advanced level will be defined with each client according to his own needs. For more details about the courses, please contact us.

Gemological expertise