AGS vs. GIA; multiple certs; how cut is graded

[Snarleyow]

PSers,

Today (well, Saturday) I had an interesting conversation with the owner of a B&M store in the PA/NJ/DE tri-state area I''m dealing with for getting an E-ring setting. They would natuarally also like to provide the diamond if possible. I brought in the 1.285ct. G SI1 ACA H&A I just received http://www.whiteflash.com/diamonds/Diamond_Details.aspx?idno=1466977 for me to make an apples-to-apples comparison with three stones (I will detail these stones later in a separate new thread) they sourced for me to look at after I was not overly impressed with their selection the last time I was in their store. He made some interesting assertions and I''d like some feedback fom the experts. As a caveat let me say that I am repeating what he said to the best of my recollection. Some of what I say here is paraphrasing. It is always possible that I misunderstood something. Let me also say that he was very friendly and agreeable and he said he didn''t even want to get into all of this until after I''d made my decision. I asked him to go on and he obliged.

1) AGS vs. GIA

He said that GIA certs are really the gold standard and that really good stones are almost always sent to GIA and that they are typically only sent to AGS if the seller is unhappy with the grading report and feels the stone may be borderline on color and/or clarity.

The seller would send the stone to AGS hoping the slightly softer AGS grading will yield a report with the next higher color or clarity, or both. Thus a H SI2 from GIA could possibly get a G or SI1 or both from AGS and therefore be able to be sold for more money.

2) Multiple Certs

The B&M owner contended that years ago AGS used to just grade the cut and really didn''t want to grade color and clarity. He said that he could virtually guarantee that the top quality AGS diamonds I see online had been sent to GIA first. If they were really top notch, he said, the seller would have both GIA and AGS certs. A diamond with only the AGS cert suggests to him that the color and cut grades may be borderline and might get the next lower grade on a GIA cert.

The unspoken suggestion here was that the diamonds from the vendors here on PS that show only AGS certs were most likely also certed by GIA, but this isn''t shown. He said that it was all "just a big game". When he heard last week from the lady at his store that has been working with me that I was coming in for the comparison and the stone I was bringing, he said he went online and checked out the stone I was buying. He said he had tried with his sources to find an AGS graded stone for the comparison that did not also have a GIA cert and was not able to find one. Basically all the good stones either were GIA graded or had certs from both GIA and AGS.

He said he was aware of one stone that had four different certs as the owner attempted to find better grades; I think he said they had two from GIA and two from AGS, one from each done in the US and one from each done in Europe (I had not been aware that AGS and GIA had labs in Europe).

Is there any way to tell if a diamond has been graded by both GIA and AGS if the vendor only shows the AGS cert?

3) How cut is graded

He made the point that the AGS cut grading system was kind of out of date vs. the new GIA cut grading system. He said the new GIA cut grade was actually superior because it took into account how the diamond actually looks, and didn''t rely purely on numbers.

The B&M owner told me that cutters were thrown for a loop by the new GIA cut grade system because GIA does not reveal the details of how they arrive at a grade, at least not so that the cutters can cut a diamond to definitely meet GIA''s top grade.
________________________

I would especially welcome an opinion from Mr. Atlas. I got my Idealscope kit from AGA and am thinking about bringing my WF 1.285ct. G SI1 ACA H&A to his company for an appraisal before I need to make a final decision whether to keep the stone before my 10-day return window expires. The B&M owner suggested it was a nice stone but that it wasn''t a strong SI1. The unspoken suggestion that it might be graded SI2 from GIA; I also now wonder if the G color grade would hold up if graded by GIA. I am concerned. Is it possible to submit it to GIA for a cert?

Thanks in advance to everyone.

Snarleyow

 

[stone-cold11]

http://grading.pricescope.com/color-clarity.aspx

Read this link. You can see that what your B&M store told you just plain wrong. He probably don't even have access to any AGS0 stone, thus the bull story about no stone with just AGS report. As you can see in that comparison, AGS is almost always stricter or at least the same in color grade while giving the same clarity grade as GIA.

The probability of a stone getting a lower grading with AGS is much higher that with GIA.

Cut-wise, I think he is the one that is out-dated. AGS change to light performance grading for RB in the 2006 if I remember correctly. GIA grading are still softer with all the rounding of numbers presented on the report. You can easily find GIA ex stone that scored a HCA score > 2 while I have never seen one AGS0 stone did that, so I rest my case there.

 

[diamondcookie]

Interestingly enough, my B&M jeweler told me that he and others he knows have seen some dodgy certificates in the last few years come out of GIA, and that he''d prefer to source for me a stone graded by AGS, if certified at all.

I think at the end of the day, you need to gather as much info as possible and see as many stones as you can, and make the decision with your eyes. GIA and AGS and EGL and whoever else can say anything they like about a stone, but you''re the one who has to wear it!

 

[honey22]

I believe your jeweller is getting AGS and EGL mixed up. She is talking about EGL. AGS is the cream of the crop, don''t worry.

 

[Paul-Antwerp]

It is worrying to have a professional jeweler tell so many untruths about just one subject, especially since it is basically unimportant for him to possibly make the sale. It makes one wonder what is true about the other education he gave you.

Live long,

 

[oldminer]

I have a feeling your recollection is adequate and it is most unfortunate. There is so little worthwhile information in what the jewelry told you that everything this person or firm tells you should be ignored. It is just one more example of how the traditional B&M jewelry indusrty is behind the times and damaging their own future.

AGSL grades many diamonds which never went to GIA and never will. GIA''s cut grade system is more liberal and dealer friendly than the somewhat tighter AGS system for cut grading. Most importantly, there is software that directs cutters how to cut GIA Excellent or AGS 0 from most any piece of rough which can become such a well proportioned diamond. Antwerp Paul is skilled enough to use this software and in cutting to be able to make this a primary business. There are many other cutting firms who have large markets for less well cut diamonds and don''t worry over top grades.

 

[WinkHPD]

Date: 10/5/2008 3:47:01 AM
Author:Snarleyow
PSers,

Today (well, Saturday) I had an interesting conversation with the owner of a B&M store in the PA/NJ/DE tri-state area I''m dealing with for getting an E-ring setting. They would natuarally also like to provide the diamond if possible. I brought in the 1.285ct. G SI1 ACA H&A I just received http://www.whiteflash.com/diamonds/Diamond_Details.aspx?idno=1466977 for me to make an apples-to-apples comparison with three stones (I will detail these stones later in a separate new thread) they sourced for me to look at after I was not overly impressed with their selection the last time I was in their store. He made some interesting assertions and I''d like some feedback fom the experts. As a caveat let me say that I am repeating what he said to the best of my recollection. Some of what I say here is paraphrasing. It is always possible that I misunderstood something. Let me also say that he was very friendly and agreeable and he said he didn''t even want to get into all of this until after I''d made my decision. I asked him to go on and he obliged.

1) AGS vs. GIA

He said that GIA certs are really the gold standard and that really good stones are almost always sent to GIA and that they are typically only sent to AGS if the seller is unhappy with the grading report and feels the stone may be borderline on color and/or clarity.

The seller would send the stone to AGS hoping the slightly softer AGS grading will yield a report with the next higher color or clarity, or both. Thus a H SI2 from GIA could possibly get a G or SI1 or both from AGS and therefore be able to be sold for more money.

2) Multiple Certs

The B&M owner contended that years ago AGS used to just grade the cut and really didn''t want to grade color and clarity. He said that he could virtually guarantee that the top quality AGS diamonds I see online had been sent to GIA first. If they were really top notch, he said, the seller would have both GIA and AGS certs. A diamond with only the AGS cert suggests to him that the color and cut grades may be borderline and might get the next lower grade on a GIA cert.

The unspoken suggestion here was that the diamonds from the vendors here on PS that show only AGS certs were most likely also certed by GIA, but this isn''t shown. He said that it was all ''just a big game''. When he heard last week from the lady at his store that has been working with me that I was coming in for the comparison and the stone I was bringing, he said he went online and checked out the stone I was buying. He said he had tried with his sources to find an AGS graded stone for the comparison that did not also have a GIA cert and was not able to find one. Basically all the good stones either were GIA graded or had certs from both GIA and AGS.

He said he was aware of one stone that had four different certs as the owner attempted to find better grades; I think he said they had two from GIA and two from AGS, one from each done in the US and one from each done in Europe (I had not been aware that AGS and GIA had labs in Europe).

Is there any way to tell if a diamond has been graded by both GIA and AGS if the vendor only shows the AGS cert?

3) How cut is graded

He made the point that the AGS cut grading system was kind of out of date vs. the new GIA cut grading system. He said the new GIA cut grade was actually superior because it took into account how the diamond actually looks, and didn''t rely purely on numbers.

The B&M owner told me that cutters were thrown for a loop by the new GIA cut grade system because GIA does not reveal the details of how they arrive at a grade, at least not so that the cutters can cut a diamond to definitely meet GIA''s top grade.
________________________

I would especially welcome an opinion from Mr. Atlas. I got my Idealscope kit from AGA and am thinking about bringing my WF 1.285ct. G SI1 ACA H&A to his company for an appraisal before I need to make a final decision whether to keep the stone before my 10-day return window expires. The B&M owner suggested it was a nice stone but that it wasn''t a strong SI1. The unspoken suggestion that it might be graded SI2 from GIA; I also now wonder if the G color grade would hold up if graded by GIA. I am concerned. Is it possible to submit it to GIA for a cert?

Thanks in advance to everyone.

Snarleyow

I am going to respond to this before I even finish reading what ever other fabrications he may have made in the rest of your post.

The statement I have marked in red is so patently bogus that it boggles the mind that any real jeweler would say something that stupid. AGS is notoriously tight on clarity to the point that many of us have begged the AGS to loosen up to GIA standards. Since GIA is considered to be the gold standard it makes no sense to us that AGS be tighter than gold.

Now I will go take three deep breaths and go back to see if his other comments are as self serving and stupid as this one...

Wink in his calling a spade a spade on a Sunday morning mood

 

[WinkHPD]

Date: 10/5/2008 3:47:01 AM
Author:Snarleyow
PSers,

Today (well, Saturday) I had an interesting conversation with the owner of a B&M store in the PA/NJ/DE tri-state area I''m dealing with for getting an E-ring setting. They would natuarally also like to provide the diamond if possible. I brought in the 1.285ct. G SI1 ACA H&A I just received http://www.whiteflash.com/diamonds/Diamond_Details.aspx?idno=1466977 for me to make an apples-to-apples comparison with three stones (I will detail these stones later in a separate new thread) they sourced for me to look at after I was not overly impressed with their selection the last time I was in their store. He made some interesting assertions and I''d like some feedback fom the experts. As a caveat let me say that I am repeating what he said to the best of my recollection. Some of what I say here is paraphrasing. It is always possible that I misunderstood something. Let me also say that he was very friendly and agreeable and he said he didn''t even want to get into all of this until after I''d made my decision. I asked him to go on and he obliged.

1) AGS vs. GIA

He said that GIA certs are really the gold standard and that really good stones are almost always sent to GIA and that they are typically only sent to AGS if the seller is unhappy with the grading report and feels the stone may be borderline on color and/or clarity.

The seller would send the stone to AGS hoping the slightly softer AGS grading will yield a report with the next higher color or clarity, or both. Thus a H SI2 from GIA could possibly get a G or SI1 or both from AGS and therefore be able to be sold for more money.

2) Multiple Certs

The B&M owner contended that years ago AGS used to just grade the cut and really didn''t want to grade color and clarity. He said that he could virtually guarantee that the top quality AGS diamonds I see online had been sent to GIA first. If they were really top notch, he said, the seller would have both GIA and AGS certs. A diamond with only the AGS cert suggests to him that the color and cut grades may be borderline and might get the next lower grade on a GIA cert.

The unspoken suggestion here was that the diamonds from the vendors here on PS that show only AGS certs were most likely also certed by GIA, but this isn''t shown. He said that it was all ''just a big game''. When he heard last week from the lady at his store that has been working with me that I was coming in for the comparison and the stone I was bringing, he said he went online and checked out the stone I was buying. He said he had tried with his sources to find an AGS graded stone for the comparison that did not also have a GIA cert and was not able to find one. Basically all the good stones either were GIA graded or had certs from both GIA and AGS.

He said he was aware of one stone that had four different certs as the owner attempted to find better grades; I think he said they had two from GIA and two from AGS, one from each done in the US and one from each done in Europe (I had not been aware that AGS and GIA had labs in Europe).

Is there any way to tell if a diamond has been graded by both GIA and AGS if the vendor only shows the AGS cert?

3) How cut is graded

He made the point that the AGS cut grading system was kind of out of date vs. the new GIA cut grading system. He said the new GIA cut grade was actually superior because it took into account how the diamond actually looks, and didn''t rely purely on numbers.

The B&M owner told me that cutters were thrown for a loop by the new GIA cut grade system because GIA does not reveal the details of how they arrive at a grade, at least not so that the cutters can cut a diamond to definitely meet GIA''s top grade.
________________________

I would especially welcome an opinion from Mr. Atlas. I got my Idealscope kit from AGA and am thinking about bringing my WF 1.285ct. G SI1 ACA H&A to his company for an appraisal before I need to make a final decision whether to keep the stone before my 10-day return window expires. The B&M owner suggested it was a nice stone but that it wasn''t a strong SI1. The unspoken suggestion that it might be graded SI2 from GIA; I also now wonder if the G color grade would hold up if graded by GIA. I am concerned. Is it possible to submit it to GIA for a cert?

Thanks in advance to everyone.

Snarleyow

This statement is also false and shows his basic lack of knowledge of the AGS laboratory''s history.

The AGS Laboratory was created because GIA would not give the AGS members a certificate with meaningful cutting information and grades. Since GIA would not do it, AGS decided to form an independant laboratory the AGSL and in a somewhat controversial move with the AGS members it was decided to allow anyone who wished to send diamonds to AGSL for grading.

Ask him how much he is willing to bet on his virtual guarantee. I know of several houses, including WhiteFlash and Infinity that do not send their diamonds to GIA, but rather send them straight to AGS since only AGS has a diamond cut grade that they consider to be serious and valid. While the GIA does have a huge portion of the diamond grading business, it is from the position of preeminence (they did it first) not because they have the best cutting grade. They only got involved with cut grades after AGS showed them that it was indeed profitable to do so.

I am not at all sure about his comment of the European AGS lab, as I do not know if they have one or not, but I think they do not. Someone with direct knowledge of this will have to respond to that comment. However, if someone were shopping grades, it would be to EGL and IGI that they would be sending their stones, not from GIA to the tighter AGS.

Here he continues to show his ignorance and self servingness. The AGS system is based on light return, with each diamond having a minimum of 40,000 rays of light traced through the diamond to see how much is returned to the eye. The GIA system is in fact based on numbers which were supposedly based on human observation and does allow for much steeper and deeper combinations than the AGS system which is based on actual performance of light in the diamond being graded. Both are basically good systems, but us cut nuts generally prefer the AGS system, although they are close enough to ensure many spirited debates here about them.

The comment about throwing cutters for a loop is even more ridicules than his other statements, the all inclusive minimum and maximum angles are clearly published for one and all to see.

I know what I would do if this were my stone, I would ask that you submitt it to GIA and then when it grades what the AGS paper said it was or better, then you pay for it. If it graded what your jeweler says, then I would pay for it. I am guessing you know why I would be willing to make this bet! I am also guessing you have a pretty good idea what I think about your jeweler, and you can please tell him I said so.

I am going to go for a walk now, three deep breaths did not work for so much misinformation. You might suggest to him that he take about a week to do some reading and perhaps take a course from both labs so that he understand what he is talking about rather than exposing his complete lack of knowledge the current state of the industry.

Goodness, no wonder the public has so much trouble trusting jewelers.

Wink

 

[WinkHPD]

Date: 10/5/2008 4:19:32 AM
Author: Stone-cold11
http://grading.pricescope.com/color-clarity.aspx

Read this link. You can see that what your B&M store told you just plain wrong. He probably don''t even have access to any AGS0 stone, thus the bull story about no stone with just AGS report. As you can see in that comparison, AGS is almost always stricter or at least the same in color grade while giving the same clarity grade as GIA.

The probability of a stone getting a lower grading with AGS is much higher that with GIA.

Cut-wise, I think he is the one that is out-dated. AGS change to light performance grading for RB in the 2006 if I remember correctly. GIA grading are still softer with all the rounding of numbers presented on the report. You can easily find GIA ex stone that scored a HCA score > 2 while I have never seen one AGS0 stone did that, so I rest my case there.

Thank you for saying what I meant to say only more politely.

Wink

 

[MissGotRocks]

Snarley I think if you have spent alot of time here on PS you would recognize the aforementioned people as experts in their fields of cutting, appraising, and selling. When I first read your post this morning, my instinct was to write ''hogwash'' - all of it. I didn''t because I had hoped that these experts we have here would chime in. They did - in glorious fashion!

They have nothing to gain from your purchase or your decision. They work in the industry everyday - not just in a B&M store selling. They are all highly regarded here and I think they have given you straight up answers to things your jeweler has said. If you had the time to read back through thousands of posts, I think you''ll find this information substantiated by many diamonds that have been purchased and shown here on PS.

Hopefully, their responses help you to understand why so many of us here would not agree with what your jeweler said. It is unfortunate that they are not more informed or that in order to sell their goods, they push incorrect and inaccurate information. Sadly, this is the norm in many cases. These type of owners are going to have to step up to the plate, inform themselves, and publish correct information. The information highway is too available to too many people today. They won''t be able to hide behind the jewelry counter forever giving out this nonsense information. They will have to do this to remain competitive in the face to today''s internet markets. That''s why we are fortunate to have these type of experts at our disposal here on PS.

Good luck with your decision - whichever stone you choose. The important thing is that you be armed with good information. An informed decision is always the best one!

 

[WinkHPD]

Well said Miss Got Rocks! I and many others salute you!

Wink

 

[Regular Guy]

Wink,

Although I am also a relative fan of AGS certification, it is not without concerns about the extent to which the claims given to its zero go beyond where they typically should. As for example, you wrote...

Date: 10/5/2008 11:13:11 AM
Author: Wink

..... The AGS system is based on light return, with each diamond having a minimum of 40,000 rays of light traced through the diamond to see how much is returned to the eye. The GIA system is in fact based on numbers which were supposedly based on human observation and does allow for much steeper and deeper combinations than the AGS system which is based on actual performance of light in the diamond being graded. Both are basically good systems, but us cut nuts generally prefer the AGS system, although they are close enough to ensure many spirited debates here about them.

Though we haven't heard much about Imagem lately...AGS should not be confused with it in principle. I know...AGS describes the earning of zero based on "light performance" but it's really the same idea of light performance that exists with GIA, when it provides it's cut grading. I think the only real difference between these two systems...since both do stratify their analysis based on an understanding of meaningful differentiation for the viewer's preference based on different variances in cut properties...is that AGS measures more closely, and it offers more categories...so it's top category is naturally better...and since it doesn't round, after it takes it's measurement, you're not having to guess about backsliding after the measurement is taken.

Importantly...no actual light performance is measured through the diamond at all. After the diamond is actually measured with AGS, a "virtual" theoretical model is created, through which the "rays of light" are traced that you describe above...but this performance is only imputed to the diamond itself. Not that such a model doesn't work too poorly. Still...to the extent to which the principle for it working is reasonable...what GIA does is not so different...with the exceptions made as noted above.

(edited to add...) well...I suppose another difference between how performance is evaluated between GIA & AGS...is that, in theory, GIA's stratification was based on clinical trials, where AGS was based on...reasonable inferences about perception and about which light ray "flows" should optimize the viewers happiness (though someone will describe this modelling approach better than me). Theoretical advantages exist with each approach...and I think the general sentiment on this board is that AGS actually takes the win on this one...but as to the more fundamental principles of comparison...really sort of agreeing with maybe a basic point Wink was making...the difference between these two systems is NOT one of substance. But...it is one of detail and execution...where the buyer may well find value in going for one over the other. But...hopefully...not because they're NOW getting the real "light performance" one.


See more here for background.

 

[strmrdr]

RG good point.
With sarin scans being used as the input there is a lot of error right there.

But while I find both systems are based on some faulty assumptions they work to varying degrees for round brilliants.
Neither will tell you if a diamond is beautiful.

 

[Rhino]

Hi Snarley,

My thought for thought ...

1) AGS vs. GIA

He said that GIA certs are really the gold standard and that really good stones are almost always sent to GIA and that they are typically only sent to AGS if the seller is unhappy with the grading report and feels the stone may be borderline on color and/or clarity.

Amongst the more popular lab Reports GIA and perhaps EGL hold a high ranking amongst lab graded diamonds you see. Amongst popular labs GIA is considered one of the most conservative. Many of us who are considered of the more conservative lot do feature diamonds with GIA Reports. With regards to the statement I have high-lighted that is just plain wrong. When it comes to clarity/color grading AGS is considered just as conservative as GIA. With regards to cut grading AGS has an 11 grade system whereas GIA is a 5 grade system. While it considered a more refined cut grading system I personally find certain elements liberal within each of their cut grading system when the totality of cut grading is taken into account. GIA may be more popular than AGS but they are not better.

The seller would send the stone to AGS hoping the slightly softer AGS grading will yield a report with the next higher color or clarity, or both. Thus a H SI2 from GIA could possibly get a G or SI1 or both from AGS and therefore be able to be sold for more money.

That's a pipe dream. I have done this in the past and for the most part GIA and AGS agree with clarity/color/polish/symmetry gradings. The biggest discrepancy I've personally seen was that of a diamond a client was purchasing with a GIA Report from us and GIA had graded the diamond as an F VS1 and AGS graded it as ane E VS2.

2) Multiple Certs

The B&M owner contended that years ago AGS used to just grade the cut and really didn't want to grade color and clarity. He said that he could virtually guarantee that the top quality AGS diamonds I see online had been sent to GIA first.

Further evidence of complete ignorance of the facts.

If they were really top notch, he said, the seller would have both GIA and AGS certs. A diamond with only the AGS cert suggests to him that the color and cut grades may be borderline and might get the next lower grade on a GIA cert.

Again not true but raises the question ... are HIS diamonds sent to both GIA and AGS? If not then the logical conclusion according to his statement is that his diamonds are not "top notch". Also, while the best way to determine if a diamond does fall in the GIA/AGS zenith for cut quality is to send it to both labs, that is not entirely necessary (although would be absolutely conclusive). If a gemologist possesses the necessary lab equipment and has studied and is familiar with the intricacies of what constitues the top grade in each lab that gemologist can determine if the stone would meet the criterial for Ex or Ideal without necessarily having to send the diamond to that particular lab. If a diamond is accompanied by a lab report by either GIA or AGS that IMHO is sufficient for determining your clarity/color/carat/polish/symmetry issues and the cut grade assigned by that lab. If you however want to know how that diamond would grade in a competing lab, best bet is to send it to that lab or to an appraiser who is intricately familiar with what constitues the top cut grade of the competing lab and has the necessary equipment/expertise to ascertain that grade.

The unspoken suggestion here was that the diamonds from the vendors here on PS that show only AGS certs were most likely also certed by GIA, but this isn't shown. He said that it was all 'just a big game'. When he heard last week from the lady at his store that has been working with me that I was coming in for the comparison and the stone I was bringing, he said he went online and checked out the stone I was buying. He said he had tried with his sources to find an AGS graded stone for the comparison that did not also have a GIA cert and was not able to find one. Basically all the good stones either were GIA graded or had certs from both GIA and AGS.

Well ... as a supporting vendor of this website I can tell you that NO AGS graded diamonds I feature have also been previously sent to GIA. If they were you'd see two lab Reports accompanied with each AGS graded diamond. What is funny is that last statement ... that all the online diamonds that were AGS graded had certs from both GIA and AGS. Hogwash.

He said he was aware of one stone that had four different certs as the owner attempted to find better grades; I think he said they had two from GIA and two from AGS, one from each done in the US and one from each done in Europe (I had not been aware that AGS and GIA had labs in Europe).

Is there any way to tell if a diamond has been graded by both GIA and AGS if the vendor only shows the AGS cert?

Ask.

We happen to publish every bit of data we can ascertain up front and of the cutting facilities I know of that send their diamonds to AGS for grading, THEY DO NOT also send them to GIA. On a personal note, the first question I do like to have answered in my own lab (and a personal criteria for my own inventory of rounds) is that if I am grading a GIA graded diamond I want to know "Does this diamond also meet AGS Ideal requirements for light performance?" and vice versa if I am looking at an AGS graded diamond ... does this AGS graded diamond also meet the criteria for GIA Ex? This requirements a knowledge of all the intracacies that constitute the top grade in each lab as well as the necessary lab equipment to make and demonstrate these determinations.

3) How cut is graded

He made the point that the AGS cut grading system was kind of out of date vs. the new GIA cut grading system. He said the new GIA cut grade was actually superior because it took into account how the diamond actually looks, and didn't rely purely on numbers.

A half truth. GIA's cut grading system is based on human observation testing (and is IMO a strength of their system) however there are certain elements that many of us feel tend towards a liberal side, particularly when it comes to steep angled proportion diamonds. Where this dude was totally off was stating that AGS' system is number based. It plainly is not. AGS system (when it comes to light performance) is primarily based on what is called "ray trace" technology whose preliminary results can be examined though a reflector called ASET (angular spectrum evaluation tool). Prior to June 2005 AGS' system was indeed "number based" but not anymore. What is funny is that GIA's cut grading system is more numbers based than AGS' is but is not purely numbers based at least with regards to primary proportions.

The B&M owner told me that cutters were thrown for a loop by the new GIA cut grade system because GIA does not reveal the details of how they arrive at a grade, at least not so that the cutters can cut a diamond to definitely meet GIA's top grade.

Muahahah. This is true. GIA, in an effort to help cutters, have released what "numbers" will make the Ex grade but those numbers also have to be tempered with a fine knowledge of painting, digging, proper visual determination of girdle thickness, etc. Some of this knowledge is proprietary to GIA and there is generally only one way to learn what will and will not make GIA Ex ... and that is to possess diamonds that fall on the cusp of grades and learn which tolerances teter over the Ex/Vg threshold.

I would especially welcome an opinion from Mr. Atlas. I got my Idealscope kit from AGA and am thinking about bringing my WF 1.285ct. G SI1 ACA H&A to his company for an appraisal before I need to make a final decision whether to keep the stone before my 10-day return window expires. The B&M owner suggested it was a nice stone but that it wasn't a strong SI1. The unspoken suggestion that it might be graded SI2 from GIA; I also now wonder if the G color grade would hold up if graded by GIA. I am concerned. Is it possible to submit it to GIA for a cert?

Thanks in advance to everyone.

Snarleyow

Dave is a fine appraiser (although Chris D'Camillo now operates the www.gemappraisers.com website) as well as Neil Beatty (www.gemlab.us) and also Rich Sherwood (www.sarasotagemlab.com) . Rich (to my knowledge) possesses the SAS2000 which is perhaps one of the most advanced pieces of technology for accurately (and digitally) determining a color grade but each of these appraisers are great at what they do. Good luck and hope that helps.

Kind regards,

 

[risingsun]

My B&M jeweler made a decision to carry the HOF line. They are all graded by AGS only. He sells very few GIA and no EGL or IGI. When we go over a diamond, we look at whether it is eye clean, loupe clean and we try to find every inclusion under the microscope and compare to the AGS plot. I use my Idealscope to check for light leakage and we use the H & A viewer, as well. We compare colors to a master set of stones. My jeweler knows better than to "romance" the stone with me. I want complete measurements to run through the HCA and compare to Brian Gavin's requirements for an ACA. I recently upgraded my top performing ACA to a top performing HOF. I have made it clear that pressuring me to buy will have the opposite effect. My jeweler has educated me and I have done the same for him. If a jeweler is doesn't know his stuff--or lies to me- I'm out of there. If they can't dazzle you with brilliance, than they may try to baffle you with bulls%&*! [to paraphrase from WC Fields]. Don't put up with it.

 

[Snarleyow]

Thank you so much to all of you: Stone-cold11, diamondcookie, honey22, Paul-Antwerp, oldminer, Wink, MissGotRocks, RegularGuy, strmrdr, Rhino, and risingsun and any others I missed for taking the time to help me.

A special thanks for the many posts from Wink and the exhaustive response from Rhino! Wow! I greatly appreciate it all. I am especially blown away by the pros taking their personal time on a Sunday to read and respond, often in great detail. Just incredible. I am humbled.

Today I will find out the final price for the setting:
http://www.goodoldgold.com/setting/VRG-ENG-0264/
The previous quote from the B&M was based on platinum selling for over $1400/oz, while now it is under $1000. http://www.kitco.com/charts/liveplatinum.html

I''ll also be making a final decision on the diamond by tomorrow.

Thanks again.

Snarleyow

 

[WinkHPD]

Date: 10/6/2008 6:34:35 AM
Author: Snarleyow
Thank you so much to all of you: Stone-cold11, diamondcookie, honey22, Paul-Antwerp, oldminer, Wink, MissGotRocks, RegularGuy, strmrdr, Rhino, and risingsun and any others I missed for taking the time to help me.

A special thanks for the many posts from Wink and the exhaustive response from Rhino! Wow! I greatly appreciate it all. I am especially blown away by the pros taking their personal time on a Sunday to read and respond, often in great detail. Just incredible. I am humbled.

Today I will find out the final price for the setting:
http://www.goodoldgold.com/setting/VRG-ENG-0264/
The previous quote from the B&M was based on platinum selling for over $1400/oz, while now it is under $1000. http://www.kitco.com/charts/liveplatinum.html

I''ll also be making a final decision on the diamond by tomorrow.

Thanks again.

Snarleyow

Just curious, are you still dealing with the same retailer that gave you all the bogus info?

Wink

 

[Rhino]

Thanks Snarley. Glad to be of some assistance.

 

[Snarleyow]

Date: 10/6/2008 4:07:27 PM
Author: Wink

Just curious, are you still dealing with the same retailer that gave you all the bogus info?

Wink

For the setting, yes, because they gave me a great price. I ultimately decided to stick with the WF ACA diamond over one of their stones. I''ll address this further in my "Battle of the Stones" thread: https://www.pricescope.com/community/threads/battle-of-the-stones-wf-aca-vs-b-m.96717/.

Snarleyow