Diamond certification

Having read with interest the letter on diamonds by Vincent Gatt of Mediterranean Diamonds Ltd (June 27) I cannot but comment on some points.

First of all, knowing that many jewellery shops are run by assistants who cannot tell a natural from a simulant, the customer cannot be certain that he is getting the right diamond in return for his money.

I agree with Mr Gatt that sometimes, the terminology used in adverts conveys to the consumer the idea that "certificated-sealed" diamonds are the best buy. However, this depends on which laboratory is issuing the certificate. Internationally recognised diamond laboratories, such as the GIA (Gemmological Institute of America), the HRD (the Diamond High Council of Belgium), GAGTL (The Gemological Association and Gem Testing Laboratory of Great Britain) and other recognised laboratories affiliated to the CIBJO (International Confederation of Jewellery, Silverware, Diamonds, Pearls and Gemstones), all have the primary aim of providing the industry and the public at large with an independent, objective opinion regarding the quality of the diamond by acting as unbiased arbitrators of standards in diamond grading, thus securing the public's trust.

Each stone submitted for certification by these institutes is carefully checked by numerous professionals to ensure maximum accuracy and grading consistency for the clients' protection. These institutes will simply not play with their grading reports. Definitely there are some diamond jewellers who will offer for sale diamonds that are accompanied by a certificate claiming to be an official document from a gemological laboratory. Sometimes such certificates show no weight, measurements, clarity, colour, diamond-inclusion plot and relevant-cut characteristics and also no value. The loose diamond may be shown to the customer loose or sealed in a plastic slide-like container with a strip of microfilm attached thereto. Sometimes this film will just display in miniature what is written on the certificate. Such diamond-grading certificates are probably not worth the paper they are written on!

Customers must be aware they have the right to get the diamond appraised by an independent gemologist. Should the customer not be satisfied with the seller's certificate after inspection by the independent appraiser, then the jeweller should agree to take back the diamond in question, even though this diamond is sealed in a special pack and the seal is broken for inspection.

An honest jeweller should be happy to agree to this, for it is in his best interest to learn that a diamond does not match its certificate. However, if the diamond is a close match and everything proceeds well with the independent appraisal, then the customer should be obliged to purchase the diamond even if, in the meantime, he may have had second thoughts.

It is also worthwhile to point out that even the certificate issued by any of the institutes mentioned above should be inspected by an independent gemologist for, in addition to verifying the quality of the stone, the customer will want to make sure that the certificate presented refers to the diamond that is being sold.

I certainly do not agree with Mr Gatt that a diamond can "unintentionally be changed with another". If a diamond is changed, this will always be "intentional" as no serious diamond dealer will treat a client's diamonds in such a way as to have them mixed.

Also, I do not agree that criteria for grading will change from time to time. It is the circumstances that change, such as light, which occasionally gives rise to different colours because of structural inhomogenities. Fluorescent diamonds for example, will simulate a "better" colour in daylight and may even give the impression of being a "rare white". When examined under a constant light-source, they may perhaps prove to be just slightly tinted white stones.

That is one reason why the internationally recognised institutes enjoy such a high reputation in their certification, since their diamonds are examined with very sophisticated machinery, such as spectrophotometers, dimension systems, and cathode luminescence apparatus, in order to ensure a high level of reliability. The internationally recognised diamond-grading systems such as the GIA, American Gem Society, Scandinavian Diamond Nomenclature (SCAN, DN) and the CIBJO all strive to achieve the highest standards when grading for colour, clarity and cut.

Normally, such an indication of the qualitative grade of a diamond is based on an analysis of size, number, position and nature of internal and external characteristics visible at 10-power magnification (exclusive of colour and phenomena). Hence it is again worthwhile to point out that a high-quality, 10X Achromatic Triplet and aplanatic eye-loupe is the standard which the GIA and CIBJO specify for the grading of diamonds. I have seen in many jewellery shops clients being asked to look at a diamond with a cheaper version of the X10 loupe that falls short of a high quality magnifier. Hence the lay customer will hardly notice what should be visible when viewed by a perfect loupe.

Finally, I have never met with internationally recognised diamond institutions that issue diplomas within a few weeks (if not days). What I understand Mr Gatt wants to say is that certain international diamond institutions can issue a diamond grading certificate for attending a workshop over a few days, but certainly not a diploma. I studied at the GAGTL in the UK and it has taken me years to study gemology in general and be able to gain an internationally recognised diamond studies diploma. I am certain that other Maltese gemologists who hold diplomas from recognised institutions can vouch that it is not easy to gain a diploma in a few weeks. I certainly do not call myself any expert and, as an appraiser, I do not deal in diamonds but I willingly give free advice on diamonds.

Mr Gatt, I strongly believe, would feel much more fulfilled if he were to obtain a Diploma in Diamond Studies from a recognised International Gemological Institution rather than just rely on the background which has given him his expertise.