The Certificate of Authenticity

Whenever you are purchasing a piece of diamond jewellery or indeed loose diamonds, you should be issued with a diamond Certificate of Authenticity (COA). This certificate, also known as a ‘diamond grading report’, assures the buyer with verification of the quality of the stone. You could say that the certificate resembles a passport.

Let’s explore this further…

You may ask the question who issues these certificates? The Certificate of Authenticity is issued by leading independent experts and the most recognised laboratories are the HRD of Antwerp (, the GIA of New-York ( and the IGI od Antwerp ( These organisations conform to global standards so it does not matter where you buy your diamonds, the ruling and validity for certification will be the same.

What does the certificate state?

The certificate will feature the 8 criteria ( that establishes the quality of a diamond and these are:

  • Carat (Weight)
  • Clarity
  • Colour
  • Shape
  • Proportions
  • Symmetry
  • Finish
  • Fluorescence

To learn more about each of the above categories visit our page on the Private Diamond Club (

What is also important to know ?

Diamonds are issued with a unique inscription that corresponds with the Certificate of Authenticity. The inscription is made by using a very fine laser onto the girdle of the diamond which can only be seen using a gemological microscope.

In general, certification is supplied for diamonds of at least 0.50 carat in size and it is worth adding that the certificate does not contain any details for the value of the diamond. This has to be done independently.

To avoid difficulty should you wish to resell or insure your diamonds, note that Certificate of Authenticity issued directly from a jeweller will not be recognised in the industry mainly because the jeweller is not considered to be an impartial assessor. It’s provenance must come from such institutes and laboratories we have recommended above.

Buying and owning diamonds is a wonderful and fascinating experience and should you wish to talk with our Diamond Expert, Mr. Yvan Delcourt, on any aspect of diamonds, do not hesitate to contact him. He will be delighted to speak with you. ( )

Guaranteed! Every piece of jewellery bought through us at the Private Diamond Club of Antwerp (, will receive a Certificate of Authenticity.


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