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Don''t fear the turf "war of words" over Diamond Cut Grading

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oldminer

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Consumers could really be put off or scared by some of the heated issues the experts make over which cut grading system is the best, and which, if any, agree or disagree with one another. The truth of all of this that it is technicalities at the upper, best end, that are being argued over. It is for the long term benefit of everyone that experts express their heartfelt opinions, but no one single system expresses all the facts and all the details. Somewhere in the midst of all this science is the visual and optical truth about what makes a most beautiful, durable, correct size and most well cut diamond. No one expert or organization has been recognized as having the perfect key to fit this difficult lock, but if you are shopping near the top of what is "best cut" you have little to fear from any of the competing systems or labs. One must always bear in mind that experts often have vested interests in making their argument and that individuals who have a superb command of the language seem to express themselves more eloquently or more knowledgeably, but they may not be as correct as someone else who has a problem with self expression. Lot''s of highly educated, computer-engineer types, are oriented more to techincal knowledge than to teaching it to others.

For people shopping at the lower regions of cut quality, there are apparently larger disagreements about what cuts grade at which level, but none are going to fool a good shoppers normal vision. Likely as not, to find a superb cut, you need shop no further than a few Internet vendors. To find a good looking compromise you may have to shop harder, visit many stores, or waste a lot of postage to find a diamond which, not so finely cut, still speaks to your heart and soul.

With round diamonds, the cut grading which exists gives results which match very well visually for the highest grades. Nuance differences exist, but your eyes won''t tell you a whole lot. Even at GIA VG, the visual results are not reliably similar on all stones.

For princess cuts, the cut grading works from AGS, but I find their AGS0 a particular type of princess cut. They tend to be excellent looking, but not the only princess cut types which are beautiful and might be even called "special".

All the other cuts are pretty much still up for grabs when it comes to defining their cut quality for the broad market. The AGA Cut Class grades do a decent job of screening potential cut quality, but much more will be done before reliance can be blindly given to purchase fancy shapes as you can do today for round brilliants.

I like a system where one could compare any shape to how top cut quality round diamonds perfom and also compares the stone to how the best range of that individual shape has performed. Using a broad database of previously examined diamonds is a good way to know where any individual stone fits into the world of its peers.
 
With rounds there is really no disagreement over a rather large range of best but where the best ends and the not best begins is where the heated debate is.
In other words there is a large overlap in the systems top grades but some extend outside that overlapping zone to a very large degree.
 
The new AGS Gold DQR Ideal range has moved slightly shallower. We are told that this proportion based (rather than the individual diamond AGS light performance test) system has had a more rigourous test establishment basis. I do not think there is any more to fear from this method as long as there is no deleterious painting or digging - which anyone buying a diamond who cares to ask our opinions here will have no trouble being protected from.

The new proportion / parameter based system has had far more research by way of assessment of virtual diamonds through a range of tilts.

If I may blow my own trumpet briefly - the new AGS Gold Ideal range has moved shallower (many less steep deeps and sevral more shallow proportions) and it has moved more in the direction of very shallow crowns - both make it more in line with the HCA research done by yours truly at the turn or this millenium - with Ideal-scope, a lap top and DiamCalc and showing diamonds to people and asking what they prefer (mostly shoppers).

Al in all, I am with Dave, that the more such info there is, the more choices we have, and frankly if this means what I believe it will - most stones that end up with this report will come from cutters who aim for AGS 0 DQD - and miss it because of sym or polish - so more better cut stones should be on the market because by and large this makes sense (although I think when AGS gets better at quantifying fire - they will include more FIC''s).

The alternative is that cutters aim for the most productive areas in GIA Excellent which in my opinion is very bad when the diamnds get a bit of yuck on their pavilion.
 
Date: 10/30/2008 6:49:56 PM
Author: Garry H (Cut Nut)
The new AGS Gold DQR Ideal range has moved slightly shallower. We are told that this proportion based (rather than the individual diamond AGS light performance test) system has had a more rigourous test establishment basis. I do not think there is any more to fear from this method as long as there is no deleterious painting or digging - which anyone buying a diamond who cares to ask our opinions here will have no trouble being protected from.


The new proportion / parameter based system has had far more research by way of assessment of virtual diamonds through a range of tilts.


If I may blow my own trumpet briefly - the new AGS Gold Ideal range has moved shallower (many less steep deeps and sevral more shallow proportions) and it has moved more in the direction of very shallow crowns - both make it more in line with the HCA research done by yours truly at the turn or this millenium - with Ideal-scope, a lap top and DiamCalc and showing diamonds to people and asking what they prefer (mostly shoppers).


Al in all, I am with Dave, that the more such info there is, the more choices we have, and frankly if this means what I believe it will - most stones that end up with this report will come from cutters who aim for AGS 0 DQD - and miss it because of sym or polish - so more better cut stones should be on the market because by and large this makes sense (although I think when AGS gets better at quantifying fire - they will include more FIC's).


The alternative is that cutters aim for the most productive areas in GIA Excellent which in my opinion is very bad when the diamnds get a bit of yuck on their pavilion.


In my opinion the AGS Gold DQR should be rejected as a watering down and less reliable system and viewed with the same suspicion if not more so than GIA EX.
I am certainly rejecting it as a selection tool.
 
Date: 10/30/2008 7:01:44 PM
Author: strmrdr

Date: 10/30/2008 6:49:56 PM
Author: Garry H (Cut Nut)
The new AGS Gold DQR Ideal range has moved slightly shallower. We are told that this proportion based (rather than the individual diamond AGS light performance test) system has had a more rigourous test establishment basis. I do not think there is any more to fear from this method as long as there is no deleterious painting or digging - which anyone buying a diamond who cares to ask our opinions here will have no trouble being protected from.


The new proportion / parameter based system has had far more research by way of assessment of virtual diamonds through a range of tilts.


If I may blow my own trumpet briefly - the new AGS Gold Ideal range has moved shallower (many less steep deeps and sevral more shallow proportions) and it has moved more in the direction of very shallow crowns - both make it more in line with the HCA research done by yours truly at the turn or this millenium - with Ideal-scope, a lap top and DiamCalc and showing diamonds to people and asking what they prefer (mostly shoppers).


Al in all, I am with Dave, that the more such info there is, the more choices we have, and frankly if this means what I believe it will - most stones that end up with this report will come from cutters who aim for AGS 0 DQD - and miss it because of sym or polish - so more better cut stones should be on the market because by and large this makes sense (although I think when AGS gets better at quantifying fire - they will include more FIC''s).


The alternative is that cutters aim for the most productive areas in GIA Excellent which in my opinion is very bad when the diamnds get a bit of yuck on their pavilion.


In my opinion the AGS Gold DQR should be rejected as a watering down and less reliable system and viewed with the same suspicion if not more so than GIA EX.
I am certainly rejecting it as a selection tool.
I think you will be proven wrong over time Storm, and your basis of the comparison with GIA Ex is foolhardy.
I hope that AGS will look more closely at painting and digging, which at the moment I believe is based on the reports they have from dealers and manufacturers as to what GIA practice is. Clearly it can be improved and past experiance with AGS is they are open to improving systems over time.

Don''t throw the baby out strom
 
Date: 10/30/2008 7:13:21 PM
Author: Garry H (Cut Nut)

I think you will be proven wrong over time Storm, and your basis of the comparison with GIA Ex is foolhardy.

I hope that AGS will look more closely at painting and digging, which at the moment I believe is based on the reports they have from dealers and manufacturers as to what GIA practice is. Clearly it can be improved and past experiance with AGS is they are open to improving systems over time.


Don't throw the baby out strom

I don't think so, a 2D system can never have the same level of confidence as a 3D system.
It is a 2D system just like GIA's just with a little different numbers.
2D systems are fundamentally flawed.
That flaw can not be fixed no matter how good the science behind the range.
At best 2D is a wide range rejection tool.
It can never be a selection tool.
 
As you know, I do not recomend any parametric system for selection. No arguement.
 
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