A Guide to Diamond Lab Certificates

Certified Diamonds - What You Should Know

diamond certificates

A diamond certificate, also known as a diamond report, is issued by an accredited independent gemological laboratory. In addition to the diamond’s carat weight and measurements, a certificate includes grades for the diamond’s cut, color and clarity. These grades are the opinion of the individual at the lab who graded the diamond, based on the lab’s own subjective grading standards. Certificates also include other information about the diamond’s polish, symmetry and fluorescence, and also a graphical depiction of the diamond showing the location of the diamond’s inclusions.

Why Shane Co. Uses Multiple Grading Labs

In addition to grading all of our diamonds ourselves, Shane Co. also uses several of the world’s leading independent diamond grading laboratories to provide a 3rd party evaluation for many of our diamonds. For diamonds graded by an outside laboratory, a copy of the report is included online and with your purchase.

Some labs tend to be looser or stricter when grading Cut, Color and Clarity, and some are more consistent in applying their standards than others. Therefore, if different labs were to grade the exact same diamond, they could give that same diamond different grades.

By using multiple labs, Shane Co. ensures that our own grading standards reflect a balance of the prevailing global standards. Remember, of the Four Cs, only Carat Weight is factual, while cut, clarity, and color are simply an educated opinion by an individual. Our rigorous approach to grading ensures that we consistently provide our customers with accurate and reliable diamond grades.

Diamond Certification Laboratories

GIA - Gemological Institute of America

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The GIA created the 4 Cs grading system. GIA is known for having the strictest grading standards of the leading labs and is also the most consistent. The GIA certificate is considered the benchmark to which all others are compared.

Go to GIA website

IGI - International Gemological Institute

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The IGI tends to grade diamonds looser in color and somewhat looser in clarity compared to GIA. The IGI is consistent in its grading standards.

Go to IGI website

AGS - American Gem Society

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The AGS was the original lab to provide diamond cut grades and uses its own cut grading scale from 0 to 9. The AGS’s grading standards are nearly comparable to GIA’s grading standards. AGS has an excellent reputation for consistency.

Go to AGS website

GSI - Gemological Science International

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The GSI's grading standards and consistency are similar to those of the IGI and the GIA.

Go to GSI website