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Gem Laboratories & Certifications

Gemology is not an exact science and gemstones are challenging subjects. Scientific techniques continue to evolve and change with the development new technologies and new challenges presented in the marketplace.

Over the last 10-15 years, the gemological sciences have grown significantly in scope and technology. The basic vital instruments for gemological purposes such as microscopes, refractive indexes, specific gravities, fluorescence and others have been used for more than half a century. But with the onset of new treatments in gemstones today, advanced laboratory equipment has been introduced in the field to identify them. Depending on the type of treatments used, the price of the gemstone should reflect accordingly.

The following are the most well-equipped, trained, experienced and respected laboratories in the world. These laboratories are used by the gemstone trade, the public, and the research community. They are dedicated to the advancement of gemstone knowledge and crystal sciences.

Gem laboratories are not flawless, but the below laboratories all belong to an international organization that has very strict credentials for membership. The LMHC (The Laboratory Harmonization Committee) shares research data with each member and has very high standards which need to be met in order to remain part of the organization. Uniform grading and reporting is consistent throughout this group. The reputation of one lab is dependent on many, so all members are very careful and concise in reporting, for this reason we strongly suggest that you only rely on a laboratory report from the following laboratories:

GIA Gem Lab (Gemological Institute of America)

The GIA is considered the premiere diamond grading laboratory in the world. Most people that have shopped for a diamond will usually be familiar with this lab. It is the oldest and most widely used gemological laboratory in the world and most respected in diamond grading. The GIA does have a colored gemstone division but it is not actively expanding or marketing its identification services on colored gemstones as much as other labs.

AGTA-GTC (American Gem Trade Association Gemstone Testing Center)

Considered the premiere colored stone laboratory in the USA, if not the world. Obviously we choose to use this more than any other lab due to its exceptional reputation in research, technology, staff, and ethics.

UPDATE: As of July 2009, The AGTA lab was forced to close due to the severe economic recession. The American Gem Trade Association at this time has no plans to reopen the laboratory. The Natural Sapphire Company has successfully purchased all of the AGTA’s advanced gemological equipment and hired the AGTA’s laboratory technology director.

Gubelin Gem Lab

In Europe, the Gubelin laboratory is the equivalent to the AGTA lab. It has a long history and an excellent staff. If you don’t see many laboratory reports from this lab in the USA it’s because of the steep shipping costs associated with sending high value stones overseas for reporting. Usually, European collectors are most familiar with this lab. The Gubelin lab also does diamond and pearl reporting.


The SSEF (Swiss Gemological Institute) is another leading laboratory in Europe. It has not been in business as long as some other European labs, but is considered to be as reputable and a reliable laboratory. Professor Dr. Hänni has pioneered some very important research and testing within the diffusion identification process in sapphires. He continues to be a leader within the trade on this important subject.


The GAAJ (Gemological Association of All Japan) is the premiere laboratory in Japan and Asia. Japan has a large market for fine gemstones, and this lab continues to lead the world in the volume of certificates issued on colored gemstones. Unfortunately, it had an experience of failing to catch some new treatments entering the Asian market (diffused Padparadschas), but has since upgraded its technology and reliability.


The CISGEM (Centre for Information and Services in Gemology) is a leading laboratory in Italy. It was established in 1966 as a small laboratory by the Italian government, but has since been privatized and is now widely used within Italy. It is part of the LMHC, and maintains the levels of reliability in reporting on gemstones to be a part of this exclusive group.


The GIT (Gem and Jewelry Testing Institute of Thailand) is located in Bangkok, Thailand. Thailand is known to be the main trading and processing center for the colored gemstone industry. Most treatments to gemstones happen in Bangkok and most of the laboratories in Thailand should not be considered reliable. The GIT has been the only lab that is committed to maintaining the highest ethical and quality reporting standards needed in order to be a member of the LMHC. For this reason we recommend the GIT and the acceptance of their reports.

Other Labs

If you are looking for information on a laboratory that is not listed here (such as one part of the LMHC International Group), then you should seek at least a second opinion on the reputation of the laboratory. The LMHC is not an “exclusive” marketing group or organization seeking to bar competing laboratories. Rather, it is an organization that shares research and reporting information within the group so that it may always improve and maintain quality and accuracy. A laboratory that is not a member of the LHMC is either not keeping strict standards or does not have the needed equipment to accurately report on gemstones.