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Diamond Certification

What are certified diamonds?


Diamonds certified in a laboratory typically include a diamond grading report or diamond certificate to authenticate several factors about the diamond. The detail of diamond grading reports varies from simple 'credit card' style reports to more detailed reports on A4-sized documents. Today, some laboratories have 'gone digital' taking information online for buyers to look up with their unique certificate number applied to each diamond. 


Popular diamond grading reports


Most jewellers supply diamond dossier reports with key information printed on a small-sized report. Dossier reports cost less to create and appeal to most jewellers and diamond merchants. In addition, their smaller size means easier storage and postage. 


Are all diamonds certified?


Not all diamonds include a certificate. The cost of certifying a small diamond makes no sense—especially when some jewellery items feature multiple diamonds of the same small size. In this instance, some organisations create a 'blanket diamond certificate' with information on the set of diamonds, rather than individual stones. 


In other instances, some diamond merchants avoid certification for poor-quality diamonds, because a specific diamond grading report will limit the sale price of any particular diamond. 


Can you trust all diamond certificates?  


No. To elaborate, not all laboratories grade diamonds strictly. When a lower colour and clarity diamond receives a higher grade, the owner can charge more for that diamond based upon the list price. Some laboratories, such as GIA and IGI provide consistent grading. For this reason, they remain very popular as trusted organisations for the creation of diamond reports. 


Below we have included details of some of the popular diamond laboratories to which jewellers and diamond traders send diamonds. 

The Gemological Institute of America (GIA)

The Gemological Institute of America was established by Robert M Shipley in 1931. Most jewellers consider GIA as a trusted provider of certification—working to the highest standards of integrity. In fact, academics, jewellers and diamond dealers all use GIA for their diamond grading. 

Some of the world's most famous diamonds undergo certification from the GIA, the Hope Diamond and the DeBeers Millennium Star. 

GIA introduced the 4 C's of diamond grading to value a diamond. Today, most diamond merchants and jewellers use this same system to value a diamond.


GIA and the digital dossier certificate


The GIA Diamond Dossier represents the first diamond grading report to go digital in 2023. In their own words, clients can access it anytime, anywhere with the touch of a finger. Furthermore, they can send it, save it, or scan it with a QR code. By using the GIA app., available to download from the Apple App Store or from Google Play, a diamond report number can be entered to verify a diamond certificate's authenticity. 


The International Gemological Institute (IGI)

IGI stands apart as one of the largest independent laboratories handling a large majority of the worlds certified Diamonds. IGI provides diamond grading services with an expansive experience of gemmological grading. Founded in 1975, most diamond merchants position IGI alongside the leading gemological institutes. In fact, IGI issues more certified diamond reports than most other diamond grading labs. 

IGI laser engraving for lab-grown diamonds


Most lab-grown diamonds feature a laser inscription to distinguish them from natural diamonds. In fact, most of our own lab-grown diamonds go through the IGI laboratory to receive this and the certificate number laser engraved on the girdle of the diamond. Each inscription requires a minimum of 10x magnification to read—best viewed through a gemmological microscope. 


The following image shows one of our cushion-cut lab-grown diamonds with the lab-grown inscription showing. 

The European Gemological Laboratory (EGL)

Established in 1974 in Antwerp, EGL now has laboratories worldwide and is an internationally recognised gemological laboratory providing comprehensive Diamond grading reports for certified diamonds. EGL Antwerp came under recent scrutiny after an industry-wide call for greater consistency and stricter grading. 

The American Gemological Society (AGS)

The American Gem Society was founded in 1996. It has been dedicated to setting the highest possible standards of business ethics and professionalism in the jewellery industry. This laboratory is regarded as one of the most reputable in the entire world. Our only criticism of this great laboratory is that there are relatively few Diamonds in circulation that are certified by AGS, but their reputation is well-known amongst seasoned jewellers. 

The HRD (Hoge Raad voor Diamant) Laboratory

Established in 1973 as the 'Hoge Raad voor Diamant' or 'Diamond High Council,' the organisation has become the major employer of the Antwerp Diamond sector. The HRD acts as spokesperson of the sector towards authorities and third parties and offers a wide range of services including the issue of certified Diamond reports for loose polished Diamonds from the HRD Certificates Department. It issues one of the world's most respected Diamond certificates and jewellery reports and is the first Diamond lab in the world that is NBN EN ISO/IEC 17025-certified.

The IGR Laboratory

IGR laboratory is a London based diamond grading laboratory. They provide a range of services and Diamond grading reports and their UK location provides a convenient location for UK jewellers ensuring a fast turnaround on Diamond certificates. The informative IGR website is nicely presented, with a great insight into the style of their reports and the range of services provided.  

The AGI Laboratory

AGI is an abbreviation for Antwerpse Gemologische Instelling. Their byline is 'understanding Diamonds.' They are located in Antwerp and Manchester, making UK Diamond certification convenient, with full-size Diamond grading reports available for Diamond submitted. Their service is speedy and reliable. They have been operating in the UK since 2000, and now have over 13,000 clients Worldwide. Like GIA, their website offers a validation service enabling owners to enter the report number for details of their Diamond.