GIA Versus EGL Diamond Grading Differences

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.

	EGL-International	GIA	Difference
Color	H	K	3 grades
Clarity	VS2	SI1	1 grade
Polish	Excellent	Very Good	1 grade
Symmetry	Excellent	Fair	3 grades
Girdle	Slightly Thick	Very Thin to Thick	3 grades
Cut Grade	Premium	Good	3 grades
Fluorescence	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.