Here's a great article I found that explains it:
http://www.jewelryeducator.com/2010/04/gia-vs-egl-certification-the-real-truth-about-diamonds/
GIA vs. EGL Certification The Real Truth About Diamonds
Apr 15th, 2010 | By admin | Category: Jewelry Information
This question has become more and more important in the recent months. I believe the reason for this is the economy coupled with the obvious price difference between EGL and GIA diamonds. At the time of this article I found a GIA certified 1.00ct Round H-SI2 for $4400 on a website, I found the same diamond with a EGL certification for $3400 on another website. So what gives? Why is there such a huge difference in pricing? The first thing that I want you to realize is that GIA and EGL do not make diamonds! GIA and EGL are not a brand of diamonds, they dont sell diamonds either. They provide independent grading services for jewelers and diamond wholesalers and could care less how much a diamond sells for or who sells it.
I think the other thing that is important to know is how the certification process takes place and how a diamond moves through distribution channel. When a diamond is first mined it needs to be polished, if you look at the image above you will see how the diamonds look un-cut. Once the diamonds are cut and polished to bring out their natural beauty and brilliance, they need to be graded for color and clarity. Let me just preference this first, the diamond wholesaler is doing the cutting and polishing. He then can choose to sell the diamonds without a certification to a retail jewelry store or have the diamonds certified by one of many grading laboratories. In most cases, the diamond will be certified before it is presented to the jeweler for sale. The increased demand by consumers to have assurances about the color and clarity have encouraged the practice of certifying just about all diamonds before being put on the market.
Now the wholesaler has another choice to make, where do I send this diamond for certification? Lets eliminate all the possibilities except GIA and EGL. If he/she sends the diamond to GIA it can take up to 6-8 weeks before they receive their diamond back. This is difficult on the wholesaler because he/she has purchased and paid for the diamond already. Its important for them to be able to sell their goods as soon as possible and GIA will hinder this. EGL on the other hand can return their goods in as little as 2 weeks allowing them to sell almost immediately. Youve heard the expression
Time is Money, right? Case in point, the longer the wholesaler has to wait for his diamonds the more money he has to sell his diamonds for. Lets assume he/she sends one diamond to EGL and one to GIA and both come back with the same quality grade. In all likelihood, the EGL diamond will sell for 15 20% less than the GIA diamond. The reason is because the GIA diamond probably took 6 weeks to get back and the EGL diamond came back 2 weeks. The wholesaler could buy and sell 3 diamonds in the time that it takes for the first diamond to come back from GIA. So when the GIA diamond comes back he has to sell it for more just to catch up with all the profit that he could have made if he chose to use EGL. Its simply a matter of economics!
The common belief is that GIA is a much stricter lab and that they never make mistakes and that all diamonds graded be EGL would be graded lower if done by GIA, this is a dangerous and naive assumption. How on earth can we assume that every diamond graded by EGL is done incorrectly? I will agree that GIA does swing in a more conservative direction than EGL however, I have seen many diamonds graded by GIA that I believed were done incorrectly. Ive been buying and selling diamonds for over 20 years and Ive sold millions and millions of dollars in diamonds, so listen to what I am going to say
..All grading labs are capable of accuracy and inaccuracy! So where does that leave the average consumer? In the hands of a honorable local jeweler that has experience and integrity and is willing to help you determine if the GIA or EGL grade is accurate. Theres still is no better way to buy a diamond than to work with an experienced professional that will examine the diamond with you and help you find the hidden values in diamonds. In my opinion, there are more opportunities for hidden values in EGL certified diamonds than GIA diamonds. The only accurate and safe assumption that can be made is that almost all GIA diamonds will sell for 15% 20% than EGL diamonds.
So with that being said, why not take the time to look at diamonds with EGL certifications to see what you or your local jeweler thinks? Lets look at a possible scenario
.you are considering two diamonds, both are 1.00ct and both are SI1, H, one is graded by EGL and the other by GIA. The EGL certified diamond is $4000 and the GIA certified diamond is $5000, both diamonds are equally brilliant and beautiful. Why wouldnt you elect to save the $1000? The only proven and non-disputed variable is the real math the EGL is $1000 less and this point cant be argued! Ask your jewelers opinion, does he think both diamonds are graded accurately? If he says that they are, why wouldnt you go for the diamond at $4000? Keep this in mind
you cant take a certification and roll it up in to a nice little ball and set it in an engagement ring. Youre not buying the certification, you are buying the diamond! Notice the extended use of my !s, this subject drives me nuts because there is so much misconception by consumers and jewelers alike. There are no guarantees that all diamonds certified by GIA are better in any way than a diamond that happens to be certified by EGL.
If you disagree then riddle me this
If I send a diamond to EGL for certification and then I send the exact same diamond to GIA for certification and get the same grading results, does the diamond become more brilliant because it has a GIA certification? Does it become more valuable? The answer on both counts is no, its still the same diamond for Gods sake! I get so frustrated because we must remember that we are buying diamonds not the certification. This can become so much simpler for you if you keep these two basic concepts in mind. If you are considering two diamonds that are EGL and GIA certified and they are the same price, same quality, and they both look equally beautiful then go with the GIA certified diamond. However, if you are considering two diamonds that are the same quality, the jeweler tells you that they are both accurately graded, and the EGL diamond is less then go with the EGL diamond.
I will say one final thing though, you will never find an EGL certified diamond that sells for the same price as a GIA certified diamond if they are the same color and clarity, the EGL will always be less. On the other hand, you will find plenty of EGL certified diamonds that are graded just as accurately as the same GIA certified diamond for much less money. You just have to do your homework and trust in a professional jeweler to help you make healthy assumptions. The choice is yours!