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GIA Versus EGL Diamond Grading Differences

GIA-logo Whenever we have a client say they found a diamond priced much less somewhere else, the first question we ask is if they are comparing similar quality and GIA graded diamonds.  We try to point out to clients that EGL, IGI, HRD and other grading reports tend to be off 1 to 3 color grades and often a clarity grade compared to GIA grading.  I wrote a blog article about this several years ago at http://diamonds.blogs.com/diamonds_update/2008/09/learn-to-play-the-certification-game.html and we encounter these types of discrepancies everyday between the grading reports.

However, some clients just do not want to believe the truth and hope they will somehow find a diamond priced for 25% to 50% less than its actual value.  We have even had clients argue with us saying that they have found online opinions that the EGL and GIA grading is the same.  We can only say that our experience has been that every diamond we have seen that was graded by both laboratories has come back with the EGL grading significantly higher ratings.

We recently had a client who requested a search for a round diamond about 1.4-carat weight with at least G color and VVS2 clarity.  After providing him several lists of recommendations for GIA graded diamonds meeting his requirements, he asked if we had any non-certified diamonds that we would recommend.  We explained that we usually only recommend GIA graded diamonds and explained about the inaccurate grading that is common with other laboratories and referenced the blog article mentioned above.  A month later, he emailed saying he had purchased a diamond from another retailer and was sending it to the GIA Laboratory in Carlsbad, CA.  He said he was able to find a higher quality stone at a lower price than we had recommended to him.

Here are the specifications for the diamond he purchased:

Round, 1.50 carat, EGL-Intl cert, H color, VS2 clarity, depth 60.4%, table 57%, measurements 7.38 x 7.33 x 4.44 mm, Excellent polish, Excellent symmetry, Premium EGL cut grade, Slightly Thick girdle, Slight Blue fluorescence

I never did understand why he thought H VS2 was higher quality than the G VVS2 he required for our recommendations.

Here are the specifications for the same diamond when graded by the GIA:

Round, 1.50 carat, GIA cert, K color, SI1 clarity, depth 60.3%, table 58%, measurements 7.39 x 7.34 x 4.44 mm, Very Good polish, Fair symmetry, Good GIA cut grade, Very Thin to Thick girdle, Strong Blue fluorescence

In other words, the same diamond graded by both laboratories came with very different grading even though the laboratories claim to use the same grading standards.








3 grades




1 grade



Very Good

1 grade




3 grades


Slightly Thick

Very Thin to Thick

3 grades

Cut Grade



3 grades


Slight Blue

Strong Blue

2 grades

The bottom line is that when you are making a significant investment, you should want to know what you are purchasing.  The GIA is the most accurate and consistent of the diamond grading laboratories so is the best way to ensure the quality of your diamond purchase.  With other grading laboratories, you do not know what you are getting as evidenced in the example above.


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What about AGS (http://americangemsociety.org) certificates? In my experience, and from things I've heard from other people, they can be even more strict than the GIA.

Denny's Reply
We find the AGS tends to be off in color so they are generally priced less on the wholesale market than a GIA graded diamond with the same specifications on the grading report.


Thank you for posting this! I am starting to shop for rings and have heard a lot of conflicting info about different labs, but the one thing I hear consistently again and again is that GIA has the strictest standards and is the most respected in the industry. So I guess my mind is made up--not buying a diamond unless it is GIA-certified.


Great article. You should post more often. At Max's Diamond Price Guide - diamondpriceinfo.com - we provide different suggested retail prices for the In Store and the Internet markets, as well as different prices based on the Grading lab. With GIA grading much more than the majority of fine diamonds available for retail sale, it is clearly recognized as the leader and your customers will not go wrong taking your advice!


Hallelujah! I keep seeing other people trying to justify the use of other labs. Why would you ever want a diamond that is not GIA-certified? They have the strictest grading standards, they are the most reliable and trustworthy, and they invented the 4 C's in the first place! I would never buy a diamond that did not come with a GIA grading report. Not worth the risk!


thanks for great article


I just finished reading your post and have been wondering exactly how far all of the companies vary in their grading.

One question I have, did the original from the EGL and the new one he got for the GIA? Or are the numbers you using estimates from your experiences and knowledge?

I have looked and asked all over for somebody that can actually furnish reports from the GIA and EGL for the same diamond.

Denny's Reply

This was one diamond going to two different labs and you can see the results. We see this fairly often and the results are much the same in every situation. We even see diamonds listed in wholesaler's inventories where it is the same diamond but listed twice, once for each grading laboratory.


Very intersting. I love learning more about diamond jewelry.


Thank you for the great article..I am happy because i am going there for a certificate course..I guess i will be trained well.

Eddie R Runner

Thanks for sharing the post..I would also love to join a school of such type.

Diamond Jeweller

GIA is rapidly emerging as the premier diamond grading lab and what is good is that it is internationally recognised too. It is also becoming an established brand in its own right too. It makes selling diamonds to customers easier as they can have more certainty about what they are buying.


Wow, thought there would be a difference but 3 grades in colour and 3 relating to diamond cut is most surprising. Suppose you pay for what you get. Stll think there is aknowledge gap amongst the general public, the view is a certificate is a certificate.

John Peter

Excellent Article about GIA certified Loose Diamonds.


Well said. People need to understand that it is a different grading altogether. You can read about it also here: http://www.peleddiamonds.com/articles/gia-gemological-institute-of-america.aspx

Janine W. Nelson-Alfke

I am a Graduate Gemologist from none other than GIA. There really is no other school. GIA has always produced high quality graduates because they practice what they preach. Integrity is everything and once you lose it you cannot gain it back.

antique engagement rings

Great blog..... gia's are the standard!

certified diamond earrings

This blog information is totally new for me. But overall is very interesting i like it.

Chris Hughbanks

I am the marketing director for Citadel Diamond Group. We have noticed in our sells that the majority request GIA, not EGL. When talking to our jewelers, each one says that EGL allows too many imperfections.

Arpan R Shah

Hello Sir,
I dont think so that igi & gia are much differ.
as in rescent cases from last 3-6 months gia grading has been worst of all time.
also it takes 30-45 working days for grading thats ridiculous.
thiers not much difference in all grading institutes,exceptonal cases happens.

Buying a Diamond

Great post! Been reading about this a lot lately. Thanks for the info!

Adrian Peters

I am in the process of grading 7 stones with EGL Canada which were already graded by Saxon Kruss-Toronto The client requested an 2/" report. I am very curious of the final outcome. I will know May 27th 2014. I will try to follow up on this journey

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