What I like about the AGS System

1. ASET shows a more critical analysis of cut.
2. AGS took reflector technologies to a new level by incorporating multiple colors, coding exactly where a diamond is drawing its light from in most circumstances.
3. Their new system doesn't arrive at its conclusion from a static viewpoint alone but considers tilt factors as well.
4. Dug out girdles are properly disqualified from the ideal grade.  ASET does a great job of weeding those out too!
5. GRADING FOR PRINCESS CUTS!!!  

What I would have changed or like to see changed...

1. If people are going to be viewing ASET imagery and compare a diamond with superior optical symmetry next to an ideal with chaotic optical symmetry, it is my opinion that the diamond with the superior craftsmanship should be rewarded for it. No optical symmetry grade?  That's ok though ... I'm instituting one. 
2. In the most common lighting environments inducing brightness a diamond does not appear as it does in an ASET scope in most circumstances.  Ie. The pavilion mains are mostly lit up when direct light sources come from above.  They are not always dark as the ASET suggests especially where the facets slope off the table (mains, stars & bezels).
3. Not as strict as GIA on the shallow combo's.  This is due to basic weakness in reflector technologies which do not always display how a diamond truly appears in common daylight environments. When angles get too shallow it contributes to greater darkness within a diamond and reflectors are not the best tool for picking this up except for extreme shallow combos.
4. No hit for painting even when it plainly impacts face up appearance in common daylight environments.  Another weakness of reflector technologies.
5. No minor facet information on the new lab reports.

In short, I LOVE THE AGS SYSTEM as I am perhaps anal when it comes to a critical exam of cut.  I like that they weeded out the steep/deeps in this critical analysis HOWEVER when a GIA Ex semi steep/deep combo is more brilliant than an AGS Ideal with painted girdles, well ... this is a hole in the system.  If technology doesn't agree with human observation, the eyes take precedence every time. Observation testing of the shallow combos should be instituted along with those diamonds with painted girdles to refine this system.

What I like about the GIA System

1. Determined by human observation testing. 
2. Encourages consumers to go look at the diamonds.
3. The GIA Excellent steep/deep combos we've seen have been more brilliant than H&A's with painted girdles.
4. Their testing revealed many proportion combinations that produce very bright diamonds and consumers can use...
5. FacetWare for free to explore these combinations. :)  Except if you want it for your Sarin machine! :(
6. The new lab reports feature lower girdle and star data which help a knowledgeable gemologist more accurately determine the appearance for the diamond.
7. GIA has clearly laid out the boundaries for their Excellent grade and after reviewing the combinations that comprise those boundaries (both on the shallow and on the steep ends) this gemologist fully understands how the conclusions were arrived at.

What I would have changed or like to see changed...

1. Clarity and Color are analyzed more critically than cut. A technology to examine more critical details of the cut (reflector?) should have been incorporated.
2. While the GIA steep/deeps are bright, the presence of leakage under the table should disqualify a diamond from the Excellent grade. If we are going to make financial differentiations between a VVS1 and a VVS2, then the same should apply to cut grading.  I can appreciate GREATLY the fact that observation testing was done but if we applied that same logic to clarity or color grading, perhaps diamonds would be more affordable?   
3. No optical symmetry grade.
4. In my opinion, a great addition to the grading report would have been the inclusion of upper and lower girdle angles.  :)

In short, I ALSO LOVE THE GIA SYSTEM.  GIA has taken major strides and has even reversed past positions to arrive at the conclusions they are at today.  In the beginning stages of their research they relied heavily upon technologies but in this gemologist's professional opinion, they have taken a turn for the better.  I can say, at this point in my research of the diamonds I've seen with GIA Excellent grades that the GIA system is a cut grading system developed by the people and for the people.  Why?  Because a diamond that receives the GIA Excellent Cut Grade will be a bright and beautiful diamond and this was determined by those who did the viewing (over 70,000 observations on more than 2300 diamonds!!!).  As a techie I always like a more critical exam of what it is I'm examining but it's not my cut grading system.

Conclusion?  I have no favorites and am friendly with the research gemologists in both GIA and AGS laboratories. Both have been super cooperative in helping me in my own research and for that I am grateful.  As a commitment to our clients in providing the most beautiful products available my signature diamonds will consist of diamonds that receive both GIA Excellent and AGS Ideal Cut grades and we list this data with each diamond on our website and can share with you the *why's* in case a diamond doesn't receive the highest grades.  You also have the ability to search by this data as well.

Thanks for taking the time to read this tutorial.

Warm regards,
Jonathan Weingarten
aka Rhino