AGS Releases New Cut Grades for Rounds

[Paul-Antwerp]

Date: 2/9/2005 6:32:30 AM
Author: valeria101

I am affraid I''ll ask for some clarification again...

The picture aparently tells me that less than the 5% approximation admissible by GIA standard is enough to make the difference between H&A and not-quite H&A. Is either of the new cut grading standards (GIA and new AGS) attempting to grade H&A ?

No need to be afraid, Valeria. I was just toying with John, but I would never dare do that to you.

H&A will not be graded by either GIA, or AGS. Within AGS'' grading, a lot of weight is put however on a pleasantly distributed contrast-pattern, of which well-formed ''Arrows'' is an example.

Live long,

 

[RockDoc]

Good Moning Paul...

I certainly understand the "two loves" concepts and reasons that you have for protecting cutting secrets.

My position on releasing information that may potentially create more cutting quality competition is good for both consumers as well cutters. I may be wrong in taking this position, but why not help and inform everyone?

Probably, these issues won''t remain secret too long. Consumers'' understanding of the concepts of cut grading and cutting problems encountered by cutters I believe will be a positive boost to consumers. Consumers deserve all the information they can receive. The decision of whether they want to consider these issues, are of their choice. If we are aware of a new change that would benefit everyone, then I support reporting this information to help with their purchasing decisions.

I am curious though, why information should be secretive, that potentially will leak out anyhow in the future? This creates a distrust of our industry. We have some very bright consumers that in some cases understand the advanced information and can offer comment that could help everyone, from the major labs to cutters.

Where the industry need a lot of help is coming up with a grading standard that will be accepted, rather than the current situation of labs grading differently.on a different basis.

One of my pet peeves is the differences between the major labs of their grading standards. Consumers assume that an EGL SI graded stone is equivalent to a GIA or AGS SI stone. Since the major labs base their grading standards from various viewpoints, this many times is overlooked by consumers. The major lab reports are not equal, and because EGL uses similar nomenclature to GIA''s grading standards, it really misleads consumers.

It is obvious that you''ve taken strides to cut diamonds the best you can, improve your quality of cutting, and produce a diamond that potentially will be among the best avalable. I wholeheartedly support and encourage this position and your willigness to share at least a portion of the future of analysis with all of us here on PS.

I don''t however feel that you need to be that concerned with competitive cutting techniques. A sorely missed fact is that there are people who are in this for primarilly profit, and those that operate with the standard of doing the best they possibly can, putting monetary gain as the primary consideration and ignoring the pride in workmanship is should be the driving goal of everyone. Your position of doing the best you can do is highly commendable, and sets you apart from other that do compete with you.

Not to bad mouth the industry, but there are only a small percentage of industry members that dedicate their every operating decisions based on a real love for what they do. Fortunately for PS, and its readers, a lot of such members of the industry in all of our various endeavors, dedicate their actions to constantly being betterand improving at what they do.
This will probably hold true in cutting... the bulk of cutters will not make the effort to improve, and the reluctance to change with the times, will leave only you and a small amount cutters who primarily cut for making the stones beautiful, in the forefront of quality.

Look at the percentage of people who are gemologists, as compared to those who take on the responsibility of grading without the even most basic of gemological education, the GG from GIA. I am not sure what the percentage is today, but when I started it was about 4%.

Rockdoc

 

[Paul-Antwerp]

Date: 2/8/2005 11:46

2 PM
Author: RockDoc
Paul & Rhino

As you all know I''ve been preaching about girdles being foundation of a well cut stone.

In Rhino''s first posting he mentions a 3.5% girdle....Since you two have the disc, and mine hasn''t arrived yet... what is your take on how significantly the girdle come into analysis.

The eightstars have incredibly cut girdles as well as very tight roundness specs. Has AGS done any comparative studies on the variations of the girdle?

Interesting to hear Paul''s opinion on how the girdle may affect light retrun on if either the GIA or AGS is paying attention to that.

When the final software comes out, by both major labs, it will be fascinating to see how they deal with this and what the differences are like in comparing them to each other.

Exciting stuff happening!

Rockdoc

I will try to answer your question in another way, Rockdoc,

Like I said before, the grading is done on the basis of the full 3d-measurement. This of course includes the girdle.

On the other hand, what you cannot see in the charts, is how the actual separate measurement of the girdle (as a measurement of possible hidden weight or a durability problem) is incorporated in the final cut-grade.

This detail is not really interesting for the consumer, since it will only come into effect towards the end of this year, with the new AGS-grading for rounds. It is on the other hand very important for cutters, preparing for the new cut-grades, and that is why I do not want to go into that detail now.

Live long,

 

[Garry H (Cut Nut)]

I have not read all this yet, but Roc the AGS system gives parameters for ''candidates'' in the same way HCA does.

But they then go further to do individual stone testing with DiamCalc and other tools based on 3D scans. Girdle painting or gouging with positive or negative effects (they can be either, depending on oither parameters) will of course be taken into account.

It seems to me AGs have moved to a new level. Until the OctoNus system is released this will be the best grading system available.

 

[Rhino]

Date: 2/8/2005 11:35:55 PM
Author: RockDoc
Hi Paul & Rhino

I should have my AGS disc shortly...

It''s really interesting how this has turned so dramatically...

I appreciate both your postings, and the research work you''ve done...

It is good to see what I was preaching about with the 40 Mystery facet stuff is coming to a much broader acceptance.

Hey Rockdaddy!

Good to cya on the boards man. We miss you!

Regarding the stuff with the minor facets ... You bet man! I believe GIA will also be taking the minor facets into account as well. It is going to be extremely interesting how this is all going to play out. Most consumers at this point are primarily still focusing on major facet measurements and not paying attention to minor facet arrangement. We are attempting to make people aware of this through our tutorials on the subject.

And it very encouraging that at least one of the major labs will grade taking these things into consideration. The switch to individual measuring of all the facets is necessary since the diamond ( round anyway ) has 57 of them.

The only ''problem'' I see with this is how much variance between each group of facets will become the standard and how it will affect the grading. Gonna be an interesting challenge for cutters to make each group equal.. maybe even impossible due to the hard side and soft side of the stone, and the ability for each facet to achieve a great polish.

Variances will play a role as well doc. I''m not sure how much tolerance they''ll allow to be considered *ideal* but that will be of interest as well. Bill ... you are to be credited with bringing this to public awareness years ago via the forums even when noone was talking about it. Indeed it has been our discussions that have prompted me into further study of these things as well.

I think the GIA is going to be facing some serious grading system decisions in the future.

It is really gonna interest me to see the results and how it will affect other labs,the selling trade, as well as the cutters and the equipment dealers.

Thanks Paul and Rhino - you''ve both made some really great postings.


Rockdoc

Thanks man! I always enjoy your posts as well.

Kind regards,

 

[Rhino]

Date: 2/8/2005 11:46

2 PM
Author: RockDoc
Paul & Rhino

As you all know I''ve been preaching about girdles being foundation of a well cut stone.

In Rhino''s first posting he mentions a 3.5% girdle....Since you two have the disc, and mine hasn''t arrived yet... what is your take on how significantly the girdle come into analysis.

The eightstars have incredibly cut girdles as well as very tight roundness specs. Has AGS done any comparative studies on the variations of the girdle?

Interesting to hear Paul''s opinion on how the girdle may affect light retrun on if either the GIA or AGS is paying attention to that.

When the final software comes out, by both major labs, it will be fascinating to see how they deal with this and what the differences are like in comparing them to each other.

Exciting stuff happening!

Rockdoc

In answer to your inquiry Rock... ABSOLUTELY YES they are going to take upper girdles angles into consideration. I''d have to verify but I believe once the upper girdles hit 43 degrees, that''s when things begin to spiral downward. Email or pm me for more details.

 

[JohnQuixote]

Dearest Headmaster Paul,

Good day and I beg of you to re-read my question and re-grade my paper(!) I was paying attention in class, kind sir... That was not ME snoring in the back row. As a matter of fact, I learned the lesson and was reading ahead in my studies, as you can see...

Citing my previous submission:

Date: 2/9/2005 5:55:41 AM
Author: JohnQuixote

I am encouraged by the discussions of minor facets. However, I hope AGS intends to be more precise than GIA. I know you''re looking at cutting guidelines, but do either of you see any hints about how the minors will be measured incrementally? For instance, will they treat length (or depth) in conventional increments of 1% ?

You replied...

Date: 2/9/2005 5:55:41 AM
Author: Paul-Antwerp
My dear John,

You disappoint me. Apparently, you were not paying attention in my class last week, and you have not reviewed the lesson. I will have to repeat it again. You naughty boy.

The charts on the CD are the ''cutting guidelines''. The charts are made for lower girdles of 80% and stars of 50%. However, there is huge difference between the cutting guidelines, and the way that AGS will grade stones. It is essential to make and understand that distinction.

Cut-grading will be software-driven, in the following way. One starts with a Sarin- or Helium-measurement (possibly OGI). The resulting full 3D-scan of the stone is entered into the AGS-software, and this will give the grade based upon the actual 3D-image of the stone. This means that the actual position and angle of each facet will be part of the cut-grade, without any rounding whatsoever.

...Which is the HINT I was looking for!
I do realize that a cut-grade cannot be established using charts - I was only wondering about the above, which you answered for me.

This is also important for anyone selling stones with another lab''s report. Even with the full Sarin-measurement, one cannot deduct a sure and certain AGS-cut grade from the cutting guidelines.

The above material is essential, and you can count on it being an important question in the next exams.

(scribbling notes) Okay...Helium...perhaps...OGI...3D...Belgian waffles...software...Live Long...

Got it.

I will try to be less naughty. Now - can I please have that extra credit?

 

[JohnQuixote]

Date: 2/9/2005 6:32:30 AM
Author: valeria101
I am affraid I'll ask for some clarification again...

The picture aparently tells me that less than the 5% approximation admissible by GIA standard is enough to make the difference between H&A and not-quite H&A. Is either of the new cut grading standards (GIA and new AGS) attempting to grade H&A ?

Val - neither will be grading H&A. My musings are actually for a hypothetical "what if" one stone has lgf78% "all around" and another has 82% "all around"... In GIA's system they would be viewed as the same - regardless of whether the stone was true, near-true or non H&A.

So...In contrast to what you might normally expect from me, this has NOTHING to do with H&A!

 

[JohnQuixote]

Date: 2/9/2005 8:31:15 AM
Author: Paul-Antwerp

No need to be afraid, Valeria. I was just toying with John, but I would never dare do that to you.

Now who is being "naughty?"

 

[JohnQuixote]

Date: 2/9/2005 12:29:12 PM
Author: Rhino

Regarding the stuff with the minor facets ... You bet man! I believe GIA will also be taking the minor facets into account as well. It is going to be extremely interesting how this is all going to play out. Most consumers at this point are primarily still focusing on major facet measurements and not paying attention to minor facet arrangement. We are attempting to make people aware of this through our tutorials on the subject.

Regarding GIA, Rhino... Did you see my illustration and discussions of the "rounding" approach they are using?

Garry''s discussion thread linked here. (so we don''t hijack your AGS thread)

 

[Rhino]

Date: 2/9/2005 12:15

8 AM
Author: JohnQuixote
The CD we received had nothing burned on it (maybe we got the ultra-duper secret version).

We requested another.

So - While we''ve got Rhino and Paul looking - Guys, I hope you don''t mind a question...

I am encouraged by the discussions of minor facets. However, I hope AGS intends to be more precise than GIA. I know you''re looking at cutting guidelines, but do either of you see any hints about how the minors will be measured incrementally? For instance, will they treat length (or depth) in conventional increments of 1% ?

Greetings Sir John,

I would think that 1% would be plenty fine regarding the minors as you generally get more variance in measuring these facets than you do the majors. .1 degree of an angle can make more of a difference in measuring the majors than the minors. Ie. A diamond with 34.6 crown angles coupled with 40.9 pavilion angles are fine ... but just bump that pavilion angle just .2 degrees and that can break the deal (for us purists In the minor facet measurements, particularly the lower girdles, those IMO should be looked at the closest as they will impact the appearance more than any of the other minors. I''m going to forward this question to someone who''ll give me a more definite answer though.

We must hope they do not march in step with GIA''s ''ham-fisted'' {-GH} approach and round to nearest 5% to make it more ''manageable''... From reports, in GIA''s system both illustrations I''ve attached would be considered 80% (lgf78% - lgf 82%).

Yes but in your illustration the increments are not just 1% but an entire 4% (from 78-82%). I do not believe AGS will round to the nearest 5%. That IMO would be absurd and defeat the purpose. If that were the case then a stone would either get 75% lg''s or 80% lg''s or 85% and those increments are way too broad. As soon as I get an email back from my contact I''ll forward the answer here.

Peace,

 

[Rhino]

The above material is essential, and you can count on it being an important question in the next exams.

OMG .. Paul ... you weren''t supposed to leak that we were all going to be tested on these things.

 

[RockDoc]

Date: 2/9/2005 11:59

8 AM
Author: Garry H (Cut Nut)
I have not read all this yet, but Roc the AGS system gives parameters for ''candidates'' in the same way HCA does.

But they then go further to do individual stone testing with DiamCalc and other tools based on 3D scans. Girdle painting or gouging with positive or negative effects (they can be either, depending on oither parameters) will of course be taken into account.

It seems to me AGs have moved to a new level. Until the OctoNus system is released this will be the best grading system available.

First, I have a stupid question ......what is the "&nbsp" I see that on a lot of messages and not sure how to read or interpret it.

Second is a clarification of the last sentence in your post. I think AGS has had the courage to move forward. the question I have is that the way you wrote it, it appears that Octonus system will replace the AGS one? or is the final grading software going to incorporate Sergy''s stuff in it as issued by AGS. ?


Rockdoc

 

[RockDoc]

One of my pet peeves is the differences between the major labs of their grading standards. Consumers assume that an EGL SI graded stone is equivalent to a GIA or AGS SI stone. Since the major labs base their grading standards from various viewpoints, this many times is overlooked by consumers. The major lab reports are not equal, and because EGL uses similar nomenclature to GIA''s grading standards, it really misleads consumers.


This is from my posting above... Didn''t want to paste the whole thing.

No one commented on this, interested in hearing what the experts think, as well as consumers.

Answer this:

Should the industry adopt ONE system so every one is doing their grading from the same page?

I think so, but am I alone in this position?

Rockdoc

 

[JohnQuixote]

Date: 2/9/2005 4

9:44 PM
Author: Rhino

We must hope they do not march in step with GIA''s ''ham-fisted'' {-GH} approach and round to nearest 5% to make it more ''manageable''... From reports, in GIA''s system both illustrations I''ve attached would be considered 80% (lgf78% - lgf 82%).

Yes but in your illustration the increments are not just 1% but an entire 4% (from 78-82%). I do not believe AGS will round to the nearest 5%. That IMO would be absurd and defeat the purpose. If that were the case then a stone would either get 75% lg''s or 80% lg''s or 85% and those increments are way too broad. As soon as I get an email back from my contact I''ll forward the answer here. Peace,

Rhino - I cannot tell from your comments if you realize that this is exactly how GIA will be treating the increments... Were you aware of that?

I realize the illustration I posted was 4% wide: The reason for that illustration was to demonstrate GIA''s impending plan (increments of 5%)... So, in case you didn''t pick it up before, GIA will treat both 78% and 82% as 80%.

It''s good to know AGS will not follow that model. I have always maintained that 1% is perfectly acceptable (and logical).

 

[JohnQuixote]

Date: 2/9/2005 8:44:54 PM
Author: RockDoc

Should the industry adopt ONE system so every one is doing their grading from the same page?

I think so, but am I alone in this position?

Rockdoc

I agree completely, but whos position?

 

[RockDoc]

From Rhino

In answer to your inquiry Rock... ABSOLUTELY YES they are going to take upper girdles angles into consideration. I''d have to verify but I believe once the upper girdles hit 43 degrees, that''s when things begin to spiral downward. Email or pm me for more details.
Rhino



I meant the actual girdle, not the upper girdles...and by 3.5% which girdle measurement are they talking about?

many ideals even the really good H&A''s currently vary most commonly from 0.7 . Weknow the girdle isn''t uniform, so seems they should be reporting not only the variances at the halves etc, but also come up with a uniform variance standard as well.

Additionally I hope they will propose a standard for the girdles on fancy shapes as well. I''ve seen some damn thick pear tips,
maybe deduct for variances that differ over a certain percentage. I''m sure we all agree that tips of marquises and pears, if the girdle is cut too think can be a durability issue in normal wear, and for setters too.

Is there any mention in the AGS material that deals with indented naturals?

Rockdoc

 

[Garry H (Cut Nut)]

Date: 2/9/2005 9

2:38 PM
Author: RockDoc

From Rhino

In answer to your inquiry Rock... ABSOLUTELY YES they are going to take upper girdles angles into consideration. I''d have to verify but I believe once the upper girdles hit 43 degrees, that''s when things begin to spiral downward. Email or pm me for more details.
Rhino



I meant the actual girdle, not the upper girdles...and by 3.5% which girdle measurement are they talking about?

finally we get some common sense - ags will measure rounds at the 16 thick parts - o this will stop cheating and makes Fred''s warping redundant - it also brings one more US lab into line with the rest of the world (only 1 biggie to go).
now all stones will be measured the same - there i no value in measuring princess or emeral cuts at the girdle valley!!!

many ideals even the really good H&A''s currently vary most commonly from 0.7 . Weknow the girdle isn''t uniform, so seems they should be reporting not only the variances at the halves etc, but also come up with a uniform variance standard as well.

Additionally I hope they will propose a standard for the girdles on fancy shapes as well. I''ve seen some damn thick pear tips,
maybe deduct for variances that differ over a certain percentage. I''m sure we all agree that tips of marquises and pears, if the girdle is cut too think can be a durability issue in normal wear, and for setters too.

Is there any mention in the AGS material that deals with indented naturals?
the new stuff only concerns the cut grades not ''surface features''

Rockdoc

 

[strmrdr]

Date: 2/9/2005 9

1:40 PM
Author: JohnQuixote

Date: 2/9/2005 8:44:54 PM

Author: RockDoc


Should the industry adopt ONE system so every one is doing their grading from the same page?


I think so, but am I alone in this position?


Rockdoc

I agree completely, but whos position?

same here but whose system?
The best way would be to adopt an entirely new system in an open standards committee type deal.

 

[Garry H (Cut Nut)]

That is what the Cut Group Master Stone Set is all about.

 

[Paul-Antwerp]

Date: 2/9/2005 8:44:54 PM
Author: RockDoc
One of my pet peeves is the differences between the major labs of their grading standards. Consumers assume that an EGL SI graded stone is equivalent to a GIA or AGS SI stone. Since the major labs base their grading standards from various viewpoints, this many times is overlooked by consumers. The major lab reports are not equal, and because EGL uses similar nomenclature to GIA''s grading standards, it really misleads consumers.


This is from my posting above... Didn''t want to paste the whole thing.

No one commented on this, interested in hearing what the experts think, as well as consumers.

Answer this:

Should the industry adopt ONE system so every one is doing their grading from the same page?

I think so, but am I alone in this position?

Rockdoc

I definitely do not agree. It is a ''communist'' way of thinking.

Grading reports and labs is a business, and in order to improve the quality of their product, they have to compete. Competing also means differentiating their product, according to the way they perceive the demand on the market.

Uniformisation will stop the drive to improve the product. Furthermore, there will then be a need for a mantle-organisation, that controls whether every lab stays in line. In the end, you are only creating one big bureaucracy, and no value for the consumer.

I hope that this short answer is sufficiently clear.

Live long,

 

[Paul-Antwerp]

Date: 2/9/2005 4

9:44 PM
Author: Rhino

I do not believe AGS will round to the nearest 5%. That IMO would be absurd and defeat the purpose. If that were the case then a stone would either get 75% lg''s or 80% lg''s or 85% and those increments are way too broad. As soon as I get an email back from my contact I''ll forward the answer here.

Peace,

Rhino, you of all pupils,

It seems that you have also dozed off in class.

AGS will not round to the nearest 5%, they will not round at all. The 3D-measurement, as it is, goes directly into their grading-software. If one can talk about rounding, then one has to consider up to which decimal or integer the Sarin or Helium measures, and the same for the grading-software.

I even think that the lower girdle length or depth will not be a number, that is part of the grading. That length is a result of the position and the angle of various facets, and this will be measured and part of the software, I suppose. The exact number is now part of the ''cutting guideline'', but I think that technicallly, this same measurement will be translated into another way of measuring and grading.

This last part will not be a part of a possible exam, since it is deduction and speculation, not knowledge.

Live long,

 

[Garry H (Cut Nut)]

The only problem there Paul is how do AGS communicate minor facet detail to manufacturers?

Without it they can have the big 3 #''s right but fail on others, and also they may be able to move out of the main parameter sizes and still get a good result if they get just the right minor facet size.

Of course this is a project that the Cut Group are working on.

 

[Rhino]

Just going through the latest responses so please forgive if any answers are redundant.

Date: 2/9/2005 8:40:58 PM
Author: RockDoc

First, I have a stupid question ......what is the ''&nbsp'' I see that on a lot of messages and not sure how to read or interpret it.

LOL... that''s funny Rock. When I first saw that too in posts and messages I thought it was perhaps an abbreviation for "NO BULLS#%T". It''s actually part of the code generated on the server when we post responses and I think is inserted behind the scenes on a line break. Leonid will know for sure. If you take note it only happens when someone is quoted and pulls that data off the server.

Second is a clarification of the last sentence in your post. I think AGS has had the courage to move forward. the question I have is that the way you wrote it, it appears that Octonus system will replace the AGS one? or is the final grading software going to incorporate Sergy''s stuff in it as issued by AGS. ?

Rockdoc

Now THAT is exactly the question that ran through my head when I read Gary''s comment above.

On another note ... I got your message on my answering machine last night. I turn off my home phone ringer at 9pm so if we haven'' been picking up ... now you know.

Peace RockDaddy,

 

[Rhino]

Date: 2/9/2005 8:59:41 PM
Author: JohnQuixote

Date: 2/9/2005 4

9:44 PM
Author: Rhino

We must hope they do not march in step with GIA''s ''ham-fisted'' {-GH} approach and round to nearest 5% to make it more ''manageable''... From reports, in GIA''s system both illustrations I''ve attached would be considered 80% (lgf78% - lgf 82%).

Yes but in your illustration the increments are not just 1% but an entire 4% (from 78-82%). I do not believe AGS will round to the nearest 5%. That IMO would be absurd and defeat the purpose. If that were the case then a stone would either get 75% lg''s or 80% lg''s or 85% and those increments are way too broad. As soon as I get an email back from my contact I''ll forward the answer here. Peace,

Rhino - I cannot tell from your comments if you realize that this is exactly how GIA will be treating the increments... Were you aware of that?

I realize the illustration I posted was 4% wide: The reason for that illustration was to demonstrate GIA''s impending plan (increments of 5%)... So, in case you didn''t pick it up before, GIA will treat both 78% and 82% as 80%.

It''s good to know AGS will not follow that model. I have always maintained that 1% is perfectly acceptable (and logical).

No kidding. I wasn''t aware that GIA will be rounding again.

I don''t like the sounds of that. For an H&A purist that is *certainly* not good for the reason you pointed out in the graphic you posted. Once those lower girdles are lengthened to a certain amount, that''s when you start to get the clefts in the hearts.

While on that subject ... clefts in the hearts is no big whoop to me *really*. The reason I say this is because it is the *face up* appearance that is and will be judged and graded by the labs and there are now some super ideals with *no hearts* that many people who have seen them even like them better than H&A''s. There is an excellent level of precision to be observed in both face up and face down positions under a scope but no hearts (I''m not talking 57 facet rounds though), but even in 57 facet rounds, there are many people who enjoy the appearance of rounds cut with longer lower girdles.

My personal preference ... I don''t like em too long or too short. I definitely believe there is a place you gotta draw the line. An ever so tiny cleft begins to form around the 80% length but that isn''t something that would make or break it especially if the balance of fire and scintillation in the *face up* appearance isn''t affected. I find that the longer lg''s contribute to increased scintillation in direct light conditions. If you lengthen them too much though fire/dispersion can take a hit at the expense of increased scintillation.

Peace,

 

[Rhino]

Date: 2/9/2005 9

1:40 PM
Author: JohnQuixote

Date: 2/9/2005 8:44:54 PM
Author: RockDoc

Should the industry adopt ONE system so every one is doing their grading from the same page?

I think so, but am I alone in this position?

Rockdoc

I agree completely, but whos position?

AGS. Especially if GIA will be rounding to the nearest 5%!

 

[Rhino]

Date: 2/9/2005 9

2:38 PM
Author: RockDoc

From Rhino

In answer to your inquiry Rock... ABSOLUTELY YES they are going to take upper girdles angles into consideration. I''d have to verify but I believe once the upper girdles hit 43 degrees, that''s when things begin to spiral downward. Email or pm me for more details.
Rhino



I meant the actual girdle, not the upper girdles...and by 3.5% which girdle measurement are they talking about?

Girdle thickness at the bezels.

many ideals even the really good H&A''s currently vary most commonly from 0.7 . Weknow the girdle isn''t uniform, so seems they should be reporting not only the variances at the halves etc, but also come up with a uniform variance standard as well.

Additionally I hope they will propose a standard for the girdles on fancy shapes as well. I''ve seen some damn thick pear tips,
maybe deduct for variances that differ over a certain percentage. I''m sure we all agree that tips of marquises and pears, if the girdle is cut too think can be a durability issue in normal wear, and for setters too.

Is there any mention in the AGS material that deals with indented naturals?

Rockdoc

Not that I''ve seen. Bill ... is your email the same?

Regards,
Jonathan

 

[JohnQuixote]

Date: 2/10/2005 3:55:58 PM
Author: Rhino

No kidding. I wasn''t aware that GIA will be rounding again.

I don''t like the sounds of that. For an H&A purist that is *certainly* not good for the reason you pointed out in the graphic you posted. Once those lower girdles are lengthened to a certain amount, that''s when you start to get the clefts in the hearts.

While on that subject ... clefts in the hearts is no big whoop to me *really*. The reason I say this is because it is the *face up* appearance that is and will be judged and graded by the labs and there are now some super ideals with *no hearts* that many people who have seen them even like them better than H&A''s. There is an excellent level of precision to be observed in both face up and face down positions under a scope but no hearts (I''m not talking 57 facet rounds though), but even in 57 facet rounds, there are many people who enjoy the appearance of rounds cut with longer lower girdles.

My personal preference ... I don''t like em too long or too short. I definitely believe there is a place you gotta draw the line. An ever so tiny cleft begins to form around the 80% length but that isn''t something that would make or break it especially if the balance of fire and scintillation in the *face up* appearance isn''t affected. I find that the longer lg''s contribute to increased scintillation in direct light conditions. If you lengthen them too much though fire/dispersion can take a hit at the expense of increased scintillation.

Peace,

Rhino - I thought you might not be aware of that. One could suspect GIA is including them more for political reasons than anything with that "stoopid" rounding. I included a link on the last page to Garry''s discussion of GIA''s forthcoming system if you get time to look-see.

The cleft in hearts discussion is a whole ''nother convo. In brief - I think I''ve read enough to understand your position on it... Cool. Our observations here are that once the split is >8% of the length of the heart there is a tradeoff that occurs in performance in less-than-direct lighting conditions. I know the B''Scope rewards longer lengths, but IMO once you pass a certain length the stone is not in optimum visual balance over a broad range of lighting. Would love to cuss ''n discuss it with you, but when you say "not too long and not too short" you''re singing a lullaby to me, darling.

 

[JohnQuixote]

Date: 2/10/2005 5

3:51 AM
Author: Paul-Antwerp

I definitely do not agree. It is a ''communist'' way of thinking.

Grading reports and labs is a business, and in order to improve the quality of their product, they have to compete. Competing also means differentiating their product, according to the way they perceive the demand on the market.

Uniformisation will stop the drive to improve the product. Furthermore, there will then be a need for a mantle-organisation, that controls whether every lab stays in line. In the end, you are only creating one big bureaucracy, and no value for the consumer.

I hope that this short answer is sufficiently clear.


Live long,

Paul, what if there were to be a "cut committee" of people from different labs, as well as scientists and even cutters?

(PS - have you re-graded my paper yet?)

 

[Garry H (Cut Nut)]

Rhino as I remeber AGS will average all 16 girdle positions - not just the 8 mains.

And Rhino this is a turn up for the books - a discussion that H&A''s are not everything. I will not intrude Sir John, I will just observe from the side lines.