Gem Identification & Certification

Have you ever heard that a stone is “certified” and wonder what this means?  Whether you’re looking at a beautiful sapphire or a brilliant diamond, there are often “certifications” given to gemstones to prove their authentication, origin, grade and/or rarity. Certifications offer buyers validation and confidence in their purchases.  They are also helpful for appraisals, insurance and reselling.  It is important to know, however, that not all gemstone certifications are created equal.  We will detail the points to look for and what to watch out for when dealing with certified gemstones.



  • A gemstone certificate is a document issued by a licensed gemological laboratory.  Some gemstone certificates only verify authenticity and weight.  Others, especially for diamonds, will also specify colour and clarity grades.  This second type of certificate will provide identifying marks and a “map” of the stone.  Some will document whether your stone has been laser inscribed and may also identify where the gemstone originated.
  • Certificates do give you identifying information about your stone, which can be used to help identify its rarity.  Certificates will not, however, give you a monetary figure for the “worth” of the stone.
  • Certificates are not always present at the time of purchasing a gemstone.  (For example, a family gemstone you’ve inherited may not have one). Certificates can be issued at any point after a purchase if it is something that the buyer wishes.
  • A reputable certification should be done by a third party, independent from the transaction.  Sometimes, the seller will offer a self-proposed “assurance of authenticity”, but this is not considered good practice within the industry.  By ensuring that any certification is done by a third party (neither the buyer nor the seller), the buyer has added assurance as to the truthfulness to the certificate’s statements.
  • Certificates, themselves, are subjective and might thus vary and disagree from time to time based on colour or clarity grades.  However, they will by and large be relatively consistent if done by truly neutral third parties that do not have a financial stake in the transaction.
  • Certified gemologists will use a gemstone laboratory to put the gemstone in question through a series of specific and exact tests to come to a final determination and, if possible, the grade assigned to the stone.  Be sure to do research on any company or brand certification that you are not familiar with.



Certifying gemstones has become a very lucrative market with a great many companies getting into the business.  If you aren’t familiar with the company providing the certificate, you should feel comfortable asking jewellers or people in the industry if they are aware of the company and what their interactions have been.  Every certificate is not created equal.  You want to ensure your certifying agency is neutral and not involved in the purchase transaction.

The American Gemological Society is well regarded in the jewellery industry in terms of their gemstone certifying process.  AGS will also allow you to verify their certificates after the fact.  The Gemological Institute of America (GIA)’s certificates are also highly regarded.

There are other labs, such as EGL, that certify a great many diamonds, but are perceived to be ‘off’ by several grades for their colour and clarity when compared to AGS and GIA certifications. Therefore, it is important that you know these differences when comparing certification from different laboratories and before taking their grades as “fact”.

GIA certification or report can be ordered by anyone.  They can do anything for you from verifying the authenticity of a stone (they have information on their website that breaks down the cost by carat weight of the stone) to a full diamond grading report.  They can also apply a microscopic laser inscription on the diamond’s girdle with a special message or code for a small fee.

Something that a certificate cannot give you, though, is a beautiful stone.  Though they may provide additional confidence in a purchase, the certificate shouldn’t be the most important item when deciding between gemstones.  Be sure to listen to your heart, but also know that a gemstone that looks good on paper might not light up for you as much as one with slightly lower grades.  Trust your preference.

Gemstones are beautiful treasures, with or without certifications.  Certifications do, however, often offer the buyer confidence and transparency for large purchases. They provide documentation for the buyer and a basis for any future transactions on that stone. They are appreciated and helpful for appraisals and insurance purposes.  Whilst they are helpful in generating confidence in the purchase of gemstones, they should not be the sole basis of the purchase; buy the stone not the paper!

Have you purchased a certified gemstone in the past or been looking at one recently? Were you unsure about what you were being told? Share your story with us.