GIA /AGS vs. EGL/IGI -- Revisited

[Caratz]

One of the first things a consumer learns about diamonds is the importance of the certificate, especially when buying online.

The diamond education sites almost unanimously conclude that GIA and AGS have the highest standards, and that certs from EGL or IGI are generally believed to be not as reliable -- and that is the reason for the premium the consumer pays for a GIA or AGS graded stone.

A little searching shows that EGL stones are often quite a bit cheaper.

My question is how inaccurate are the second tier labs? HOW MUCH error is there in their grading?

Let's say I want to get a G stone with SI1 clarity. I've been told that I cannot rely on an EGL certicate that says that the stone is G-SI1 because EGL standards are too lax. Well, what if I go out and get an EGL-certified stone and the certificate says that the stone is a F-VS2? Can I be comfortable that the stone is really and truly AT LEAST G-SI1 (and hey, it might actually be F-VS2)? If I have an EGL stone and the certificate says its an E-VS1, should I have any confidence that GIA would grade the stone at least G-SI1?

 

[Caratz]

Here is a followup example to my last message:

I did a random check -- I am not thinking about buying either of these stones and I know the cuts are not good. This is just for comparison purposes:

Suppose I want to buy a G color SI1 clarity stone. For $4500 I can get either:

a 1.03 ct F VS2 60/60 with EGL certificate
a 1.02 ct G SI1 60/60 with GIA certificate

Let's say the EGL certificate is wrong and the stone is really G SI1. So what? So the certificate is wrong. I don't care because I wanted a G/SI1 stone anyway. On the other hand, let's say that the EGL certificate is right. Then I got a better deal by going with the EGL stone, didn't I?

 

[larry]

Some experts on the forum say EGL can be off 2 grades compared to AGS or GIA. If this is the case you might be buying an EGL certified H SI2 for the same price as the GIA graded G SI1. Doesn't sound like a great deal to me. Best bet is to contact the retailer and verify the grading with an independent appraiser and only agree to buy the diamond if it checks out to be accurate.

 

[Jess]

I would like to mention that on another thread David Atlas (I think) SUGGESTED a EGL stone (for price sake), but pointed out that it should be EGL USA, not europe or israel. It seems that the American labs are more reliable than the ones overseas. Still, varifying it with an ind. appr. is the best bet with any cert. agree with the vendor that if it doesnt match, you arent obligated to buy.