I have discussed the issue of different diamond grading labs in the past and whether it is important to get a lab certificate for your diamond. There is an interesting article out today regarding two law suits against a jeweler regarding diamond grading. It’s important to note that a diamond grade is someone’s OPINION, it is not definitive. Two different very experienced, well respected appraisers can give two different grades for the same diamond. The grades should be close, but they may be slightly different.
Likewise, different labs will grade diamonds differently as well. Some labs, such as EGL noted in the article, are known for giving generous grades. GIA on the other hand, established the diamond grading system, so I trust their grades over other labs. Still others believe AGS, another respectable lab, is the most strict in terms of diamond grading.
The bottom line is, you will likely get what you pay for. If you get a “killer deal” on a VS2, GH diamond, it was probably graded by a lab that grades generously. If the diamonds noted in the article came with GIA Grading Reports, I’m sure the consumer would have paid a much higher price for them because the grading would be more accurate.
I am very careful not to sell any diamonds with EGL Grading Reports. I’m a GIA-trained Graduate Gemologist, so if I’m going to sell a diamond with a report, I want it to be a GIA report. Of course, I probably lose sales to people who don’t understand that some labs grade generously. I’ve had customers tell me they don’t care which lab grades their diamond as long as the report shows the quality specs they want. So they will pay less for an EGL graded stone because of what the grading report says. Even though in many cases GIA would grade the stone much lower on the quality scale.
In any case, I don’t think the jeweler should be held accountable for the grading report provided by an outside lab, unless there was some deliberate deception on his part. Besides, the stones were probably priced much less because they were graded by EGL. That’s my two cents.