Today I will focus on another less understood but often referred to factor in diamond purchasing: Diamond certificates, their use, limitations and level of reliance on it for buying without viewing the actual diamond.

So what is a diamond certificate? A diamond certificate is a type of gemological authentication report that gives an identification and description of the stone , in this case, diamond being considered. This is different to a valuation, that a jeweller will usually issue, where a value is attached to the diamond or complete ring referring to the diamond certificate where applicable and market value based on customer scope is considered see below example.


Diamond certificate reports usually come in a short identification or more comprehensive identification report. There are a vast number of diamond grading institutes worldwide and some regions the preferred laboratories differ. The top 5 certificate companies in my experiences worldwide in shown below in no particular order: GIA, IGI, HRD, EGL and AGS. All these companies have similar details on their reports with some being more expansive than other and all have shorter "mini" certificates and the more detailed certificates usually over 1ct size due to the additional fees they charge.

The above pictures are the full certificates that are the more detailed ones. The following ones are the shorter summarised certificates called mini reports or dossiers depending on the laboratory that issues them:


The mini reports due to the limited information cost considerably less to have certified and identifies the main 4 C's attributes usually colour, size, clarity and cut grades. The purpose of diamond certificates have always been to serve as a 3rd party opinion on a specific diamond that is seen as being an objective opinion in general. So here we need to first have a look at limitations or disclaimers on all diamond reports and why so many laboratories and is there a legal fixed standard to adhere to for consistency? Well have a look the the report content in limitation and also same company name EGL (European Gemological Laboratory) but completely different reports and logos, why?


Laboratories put disclaimers on their certificates because in the end it is an opinion on a diamond's characters and not fact to rely on. Many people worldwide assume the colour and clarity grades etc are a fact of law where it is not but merely a convenient method that was adopted by the majority of the industry in the latter part of the latter part of the last century. This causes a more subjective range of what is what in colour , clarity etc. This gets amplified even more as is evident between assigned grades for diamonds that differ between laboratories. It is not uncommon for a diamond to receive different grades from different laboratories and mostly it is close but it can vary a lot too. This is a current ongoing issue in the industry as the main issue is the grading used is not a legal measure but an industry tool that got accepted over time. This causes noticeable discrepancies at times that one must be aware of. 

The other factor is also the motif and structures of the laboratories worldwide. Most laboratories are profit driven companies and some are not for profit companies. This could cause issues with profit driven laboratories being "forced" to be more lenient with grading for a big diamond supplier or group that uses a branch and gives them lots of business. As I mentioned on grade up or down could mean 10-20% price swings. The problem here is you also have one brand being franchised over the world and this can cause differences in the grading standards too. All these factors causes diamonds to be graded higher or even lower in rare cases than the overall acceptable range. The good news is a lot of these tricks or manipulations are caught in the market price for certain laboratories on average and this causes some certificates to trade lower than others depending on the laboratory that graded it. 

The best insights I can give here is if given the chance compare different certified diamonds with one another that has very similar specifications. If you see noticeable differences with your eye than good eliminate the less desirable if the price is comparatively close. If look the same for the larger part then go with the more value for the dollar. In the end it is what you see. Most diamond trading has been done for 100's of years without the grading as this is a new era with it's own challenges as mentioned above. In my experience the most even reporting is with the GIA (Gemology institute of America) and is most know worldwide, however I also had discrepancies in my view but in general they are very reliable.That doesn't discard a lot of other laboratories that are also quite consistent but then I take into account the branch or region of the laboratory. I found USA, Belgium and South African branches to be very consistent and close in line with GIA and in some cases even more strict in grading.


So how much reliance must one put on these certificates especially buying directly online? Well short answer is enough but it is far from the Alpha and Omega when is comes to absolute reliance on merely the paperwork. For one thing it is a paper report of someone's opinion of the stone that is subjective albeit a diamond grader. You first have to marry the paper and the diamond together. In modern times say last 10 years especially laser inscription has become popular to track a diamond by matching the serial certificate number to the report. However this is not a full proof case as fraudsters can also laser engrave any certificate number on the girdle, but this has been in rare cases and reported. A lot of the certificates also have a lot of entertaining graphs that does not mean much in itself. There are also , as I pointed out in previous blogs, certain clarity and luster factors that do not affect grades directly but are mere comments in reports that definitely impacts the appearances.

So in conclusion I would use certificates as a base point of knowing the basics of a diamond. In the end seeing is believing and I would compare diamonds across certificates with their prices and decide for myself if the differences in what I see if worth the difference in price points because in the end the certificate is a subjective 3rd party opinion on a diamond that can change depending on who grades it. I would be careful therefore to merely "buy" the certificate online without seeing the diamond and making informed comparisons with other same grade diamonds because a certificate is not the all and everything of a diamond. Always buy after seeing and comparing where you deem necessary.

I trust this gave more insight into the diamond certificate area and shows the place for it and the level of use. The coming weeks I will go more into alternatives to natural diamonds in terms of looks with stones such as White Sapphires, Moissanites, Synthetic Diamonds , Cubic zirconias etc. Looking forward it's always a fun and often asked subject so I hope I can shed light on the matter!      



David van Niekerk