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GIA Ex & AGS Ideal: The Consumers Speak

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Is There Life in the "Ring of Death"?

Over the course of time I have coined a term called "the ring of death" to refer to stones that leaked light under the table in what gemologist Mike Cowing MS, FGA, A.S.G would call "the middle ring" (see illustration to right courtesy of ACA Gem Lab).

Here is a reflector image example of a diamond exhibiting this feature.

For this study we are going to examine, in detail, a very controversial type of cut quality GIA is considering as an "Excellent" in their new cut grading system in January of 2006 which clearly does not make the AGS ideal grade. Many folks feel that GIA included this particular type of diamond in their "Excellent" grade as a cave-in to industry pressure, i.e. inside political reasons. This diamond reveals, more than anything the major differences in philosophies to the Grading Systems each lab is instituting and is a study I entered with probably more skepticism than any of my peers.  On another section of our website you are going to learn about the technologies we utilize in our purchasing decisions and how their results correlate to practical observation however this diamond we recently received into our lab helped me understand more about the GIA Cut Grading system than anything else.  In the past I have been accused of accentuating technologies over human observation but that couldn't be further from the truth. If a diamond has a change in optics that are noticeable to the human eye, what we see with our eyes always takes precedence over what any technology says.  In the following study we showed consumers the following 2 diamonds to get their unbiased input.

What is interesting about this particular study is that of the diamonds used, one is a GIA Excellent and not an AGS Ideal while the 2nd stone is an AGS Ideal which doesn't make GIA's Excellent grade (because of a feature called painting which you'll read about shortly).

Firstly here are the technological stats.

Helium Scan Profiles
GIA Excellent AGS Ideal
DiamXray Analysis
GIA Excellent AGS Ideal

IdealScope images

GIA Excellent AGS Ideal

ASET Analysis

GIA Excellent AGS Ideal

HCA Scores

GIA Excellent AGS Ideal

Diamond

BrillianceScope Results

 GIA Excellent

 

 AGS  Ideal

 

 Isee2 Results

 


This one seems like a pretty cut and dry decision eh? All these technologies are pointing to one stone!

Well, think again. 

As  you view this photograph taken under diffuse day lighting it becomes apparent which is the brighter stone.  When it came to human eye observation the stone on the left took precedence.  That stone is the GIA Excellent!

Since we only recently acquired this GIA Excellent we have only been able to interview 15 people with it so far but plan to interview more.  To our surprise, unanimously, consumer opinion chose the GIA Excellent when viewing both diamonds under...

  • Diffuse daylight fluorescent lighting (for brightness)
  • L.e.d. spot lighting (for fire/dispersion)
  • A combination of the 2.

Before conducting this experiment I showed the same comparison to our staff in which everyone on our staff was able to note these differences as well.

This isn't the first time human observation contradicted the results from technology.  It just so happens that this observation happens to contradict every technology we are aware of and I would stress once again ... The only technology the consumer goes home with at the end of the day is their own eyeballs.  Not a Hearts & Arrows viewer, not an IdealScope, BrillianceScope, Isee2, etc.

This research and observation help all of us to understand the logic behind the GIA Cut Grading system and why human observation testing took precedence in GIA's final outcome.  Surely I'm not without my criticisms but we'll cover that on our final page.

What does this teach us?  Many conclusions can be drawn from this study. One simple one is that many technologies cannot distinguish the feature of painted and dug out girdles except for the human eyes and knowledge of how to detect these features.  From my conversations with one of the members of the GIA Cut Research team, he couldn't emphasize enough ... we are trying to encourage people to *see* diamonds and compare.  Only then will they begin to understand how we arrived at our conclusions.  

I couldn't agree more. 

So ... Is there life in the ring of death? Well ... we can at least say that diamonds with slight leakage under the table are brighter and more fiery than Ideal Cut diamonds with painted girdles! While that GIA with the ring of death shows better optics than a painted girdle ideal, it still would not make my signature line because each of our diamonds must not exhibit visible leakage under the table.    And contrary to what some may think consumers prefer its appearance over an H&A with a painted girdle.  As other combinations arrive in our lab, if we note a decrease in brightness, fire & scintillation we will report that as well but from what we can observe.  If one were to ask me, if these were the last 2 diamonds on earth I would have to side with the GIA Ex steep deep.   Good thing these are the last 2 on each because I personally wouldn't purchase either.  

On a side note ...

While this did turn out to be quite a surprise for us, we have, in the past conducted observation testing between a similar AGS Ideal (painted girdle) next to another AGS Ideal without a painted girdle that we typically stock, representing 2 different flavors of Ideal cuts we featured back in 2000-2001. After roughly a year of observation testing with that comparison amongst consumers I can tell you with full confidence that over 95% of the observers picked the stone on the left in the below observation.  While there were differences in minor facet construction (lower girdles, stars and upper girdles), GIA has put their finger on precisely what it was in these diamonds that are causing the unwanted extra darkness.  It was the girdle cutting. Ie. painting in this particular instance and it was for that reason that we only stocked very minimal stones with that feature since then.

Both diamonds exhibit superior craftsmanship however one is brighter than the other.

Of the observation testing we've performed with these 2 diamonds over 95% of our observers chose the stone on the left.  Do the eyes have it? YOU BET!


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Article Contents
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2.
3.
4.
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6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Contrast
Brightness
Light Leakage
Fire/Dispersion
Scintillation: The Art of The Dance
Scintillation: Patterned "Static Scintillation"
Scintillation: Patterned "Dynamic Scintillation"
Scintillation: To Pattern or Not To Pattern?
Scintillation: Sparkle
Painting and Digging: Intro
Painting and Digging: The Classic Ideal
Painting and Digging: Dug Out Girdles
Painting and Digging: Painted Girdle
GIA Ex & AGS Ideal: The Consumers Speak
Optical Symmetry
Cut Grading: Final Thoughts