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Gemstone Laboratories and Certifications

It is so important with any gemstone to understand the certification and the laboratories that have the best knowledge and practices in the field.

An Overview of Gemstone Grading Labs

GIA certificate padparadscha sapphire
An example of a GIA certificate for a padparadscha sapphire.

The gemological sciences  have grown in scope and technology at a high rate in recent years. 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 advanced treatments in gemstones today, advanced sciences have been introduced in the field to help identification.

Now it is necessary to use highly developed instrumentation on many of the gem materials examined today. Depending on the type of treatments used, the price of the gemstone should reflect accordingly. It is necessary to have sophisticated laboratory equipment to make a judgment on most gemstones today to accurately identify these stones.

This list reflects the most well-equipped, trained, experienced, and respected laboratories in the world. Most have gemologists on staff, who have dedicated their entire careers to the study of gemstones and the many treatments that they undergo. The gemstone trade, the public, and the research community use these laboratories that are dedicated to the advancement of gemstone knowledge and crystal sciences.

Gubelin certificate heated sapphire
Gubelin certificate stating that a sapphire is heated.

If you do not see a laboratory below that you were told is reputable, we suggest you ask that laboratory some more questions about its qualifications. 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 Manual Harmonization Committee) shares research data with each member and has very high standards that 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 is dependent on many; 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 institutions:

GIA Gem Lab

gia lab seal
The seal of the Gemological Institute of America.

The GIA (Gemological Institute of America) 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.  They have a well staffed colored-stone department, although it is not always considered as reliable as some other laboratories listed here specifically for colored gemstones. For diamonds, GIA is considered the best lab.

Gubelin Gem Lab

ggl lab seal
The seal of the Gubelin Gem Lab.

If you are in Europe, the GGL (Gubelin Gem Lab) is the premiere colored gemstone laboratory. It has a long history and an excellent staff. If you don’t see many laboratory reports from this lab in the USA it is because of the large shipping costs associated with shipping high value stones overseas for reporting. Usually, European collectors are most familiar with this lab. The Gubelin lab also does diamond and pearl reporting as well. We recommend it highly.


ssef lab seal
The seal of the Swiss Gemological Institute.

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. We recommend the SSEF highly.


dsef lab seal
The seal of the German Foundation for Gemological Research.

The DSEF (German Foundation for Gemological Research) has been in business since 1969 and made a name for itself with quality research in the field. The lab is located in the heart of Germany’s gem producing region, providing them ample opportunity to assess a high volume of stones to aid in their comparisons.


cgl lab seal
The seal for the Central Gem Laboratory.

The CGL (Central Gem Laboratory) 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.


git lab seal
The seal for the Gem and Jewelry Testing Institute of Thailand.

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 its reports.


Founded in 1996 by Dr. Adolf Peretti, GRS research has focused principally on the identification and characterization of high-quality colored gemstones from newly discovered mines, as well as the determination of origin for gems derived from classic mining regions.  They have a focus of expertise in color grading and gemstone color brandings, such as the well-known GRS-type Pigeon’s Blood rubies and GRS-type Royal Blue sapphires. They have lab locations in Hong Kong, New York, Bangkok and Switzerland. The GRS website can be found here.

Now that you have learned about the most reputable gemstone laboratories for grading sapphires, discover even more about the important sapphire qualities to look for in Sapphire Essentials.


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