Bridal Jewelry Diamond Grading Labs
Consumers need to be made aware that there are variations between different diamond labs when making a purchase. For example a diamond should come with a grading report from a well known and reputable lab. This doesn't mean a diamond without a report is bad, many reputable jewelers offer uncertified diamonds with their own brand name or appraisal included. However for "important" diamonds or ones that are very rare, high quality, or stated to be natural fancy color, it's always important to get a grading report you can be confident with.
The main Gemological Grading Labs in the United States are as follows:
GIA (Gemological Institute of America) - The foremost authority on diamonds. They set the standard for accuracy in grading diamonds especially based on color and clarity. Labs from all over the world usually carry GIA master set stones to compare colors and clarity grades when they're uncertain how to grade a stone. All truly "important" diamonds are sent to this lab above all others.
AGS (American Gem Society) - Currently this lab sets the standard for precise measurements of cut parameters. No other major lab in the world goes through such detailed analytics to properly determine if a diamond is cut to ideal proportions or not like the AGS does.
EGL-USA (European Gemological Laboratories - USA Division) - This lab is a major player in the US with more labs then any other. Their passion for their work and commitment to the diamond industry to provide fast, accurate and dependable grading has given them a prominent place in this market. Unfortunately EGL-USA is in a legal dispute with EGL-International which has been flooding the market with diamonds that have not been graded as stringently. When purchasing an EGL graded stone, be sure to insist upon EGL-USA only unless you and your jeweler are able to scrutinize the stone in question well and be assured it is as advertised.
PGS (Professional Gemological Services) - This is a much smaller lab however they are well known for their accuracy and precise grading. They also offer light performance and other metric analysis other labs do not. Currently PGS does not have much market share in the diamond industry so finding a stone graded by them is rare.
All Other Labs - If you come across a diamond that is graded by a lab other then those mentioned above, do your due diligence in researching the lab to determine if their grading is credible or not. Perhaps even hire your own independent appraiser to verify their findings.
Additional Advice - Although some labs have a better reputation then others, they are all run by people who grade things like color and clarity based on their eyes, so at the end of the day, it's all a judgment call by a human being, not a machine. No lab gets it right 100% of the time, and any given stone can be graded differently even by the best labs. So always scrutinize and compare every major diamond purchase you intend to buy to other diamonds to determine if the grade is accurate.
