Here are my reviews and thoughts on Diamond Grading and Diamond Certificates; in my order of preference;
The “GIA” Gemological Institute of America has a long and highly reputable history of accurate diamond grading. After all they were the inventors of the 4 C’s diamond grading system that we use today.
The GIA has a global influence with office all over the world. The offer an abundance of courses for the amateur or professional gem enthusiasts. Since the 1930’s the GIA have developed and sold their own range of certified Gemological equipment for not only their own staff but for scientists, researchers, educators, engineers and Jewelers.
Their world campus headquarters is located in Carlsbad, California in the United States.
The “AGS” American Gemological Society is another gem laboratory based in the United States . Their laboratory is also highly recognized for their consistent scientific approach and research into diamond cut grading. Instead of using an alphabetical rating method like that introduced by the GIA, AGS uses a scale of 0-10 for rating a diamond’s characteristics, with 0 as the best and 10 as the worst. It takes a little bit of getting used to when reading their certificate but it does make sense when reading through them and comparing other diamonds.
Like the GIA, AGS has certification labs around the world as well as being the first major lab to offer diamond grading reports with a Cut Grade for fancy shapes, including Princess, Emerald, Oval and alternate cuts .
The “ADGL” Australian Diamond Grading Laboratory is an independently owned and operated lab however utilises GIA ‘Facetware’ GIA ‘FacetScan’ and other reputable testing equipment. The ADGL is based in Queensland Australia and is operated by a diamond grader with over 30 years of experience in GIA and GAA ‘Gemmological Association of Australia’ training.
Having an independent laboratory tested diamond shows little or no bias as they aren’t actually selling the diamond. In fact quite a few diamonds certified I have seen have
The IGI – International Gemological Institute is more widely known in Europe and throughout Asia, with offices all over the world. It too was formed in the mid seventies and has slowly progressed to become a common name in the industry.
A few years back myself and a number of other gemologist’s have seen and heard of diamonds being graded higher than they really are. However with the world now one they reputation means everything and no one can hide, they have picked up their game. The last few diamonds I have come across are accurate in their grading.
The “EGL” European Gemological Laboratory was founded only founded in 1974 in Antwerp Belgium. Although relatively new in the diamond grading world the “EGL” is one to be vary wary of. They are an independently run ‘For-Profit’ business. I personally would not purchase a diamond with a certificate from this Lab and hold a higher regard for the above 4 on their certifications.
These are only a small list of Diamond Labs, Institutes around the world with many others having reputable certificates when using calibrated gem testing equipment.
Remember!, ‘empower’ yourself with knowledge, some gem merchants and Jewelers will tell you just about anything to sell the stock they already have. If they have a few diamonds with EGL and other certificates from unknown certifiers they will want to sell those instead of getting in others with higher regarded certificates. Another option for you to consider is requesting the jeweler organise another certificate from a Lab of your choosing. Sure they may say it will cost extra, but negotiate and you may get it done for free if they are really keen to sell the diamond.
If they appear reluctant and try to talk you out of obtaining another certificate its probably because the ‘E’ Color ‘VS1’ diamond they are showing you is not what it appears, so you win without spending a cent. Locate another diamond they aren’t that rare.