Please rate these Cut Angles!

[soontomarry2]

I looking at a particular stone with these angles:

Crown Angle: 33.5
Pavilion angle: 40.8
Depth: 59.6%
Table: 59%
Pavilion Depth: 40.8%

Does the table seem large and the crown angle small? Interesting, it does well on the Holloway Cut Adviser and it is rated as GIA excellent.

In person, the stone looked great, but maybe one with more ideal cuts would look even better?

 

[yssie]

Numbers are fine, IS to confirm.


60/60s can be gorgeous with the right combos

 

[Dreamer_D]

Do a search on 60/60. It is a style of cut that has a distinct look. Some love it and some prefer a smaller table. I believe the 60/60s excell at brilliance.

 

[Lorelei]

Date: 3/2/2010 9:47:52 PM
Author: yssie
Numbers are fine, IS to confirm.


60/60s can be gorgeous with the right combos

Ditto

 

[Paul-Antwerp]

Date: 3/2/2010 9:22:48 PM
Author:soontomarry2
I looking at a particular stone with these angles:

Crown Angle: 33.5
Pavilion angle: 40.8
Depth: 59.6%
Table: 59%
Pavilion Depth: 40.8%

Does the table seem large and the crown angle small? Interesting, it does well on the Holloway Cut Adviser and it is rated as GIA excellent.

In person, the stone looked great, but maybe one with more ideal cuts would look even better?

The stone passes the first rejection-test of HCA, and you also like it, when viewing it in person, so there is a good chance of it passing the next rejection-tests (IS, ASET, ...) too.

But nobody but you can answer your highlighted question. Only you can compare and assess whether you appreciate a better-cut stone and if so, if you consider its probable premium appropriate.

Live long,

 

[ChunkyCushionLover]

Date: 3/3/2010 6:03:29 AM
Author: Paul-Antwerp

Date: 3/2/2010 9:22:48 PM
Author:soontomarry2
I looking at a particular stone with these angles:

Crown Angle: 33.5
Pavilion angle: 40.8
Depth: 59.6%
Table: 59%
Pavilion Depth: 40.8%

Does the table seem large and the crown angle small? Interesting, it does well on the Holloway Cut Adviser and it is rated as GIA excellent.

In person, the stone looked great, but maybe one with more ideal cuts would look even better?

The stone passes the first rejection-test of HCA, and you also like it, when viewing it in person, so there is a good chance of it passing the next rejection-tests (IS, ASET, ...) too.

But nobody but you can answer your highlighted question. Only you can compare and assess whether you appreciate a better-cut stone and if so, if you consider its probable premium appropriate.

Live long,

"Probable Premium Appropriate" PPA that should be a new term used often here. This should be the new Pricescope FAD!

This is at the heart of why I am extremely positive about stones cut for light performance and super ideal cut diamonds in all shapes, and really pushing for consumers to make an informed choice between these and other diamonds which may have other redeeming qualities.

---------------------------------------------------
Simplifie Example:

Customer walks into a diamond shop of a vendor who doesn't use modern technology for diamond selection and only sells non branded or non ideal cut diamonds:

Dealer shows them 10 diamonds they are all pretty no surprise, diamonds in jewelry store lights usually are.
Customer being diamond savvy views the diamonds in the window, under a table etc. and then finds now only 3 are pretty to them in different lighting.
Dealer says "trust my experience and what your eyes see" and suggests 1 of the three.
Customer purchases that diamond and is confident they chose the most beautiful diamond for them. After all it was the best one out of the 10 and the "expert" dealer said so.

Now customer walks down the street and looks at some branded ideal cut H&A diamonds with all the reflector tests available, priced 10 - 20% more and says wow my "most beautiful" diamond isn't as beautiful as these ones I wish I had paid the premium.

or

The customer looks at the branded diamonds and says well these are beautiful too but not 20% more beautiful than what I bought I am happy with my decision.
-----------------------------------------------------

I wonder at which place will the consumer receive a better education and make the most informed decision? That may be a tough one, we all can infer that the vendor selling non super ideals isn't going to show the consumer a super ideal they don't sell them. But will the vendor selling super ideals show the consumer the best cheaper non branded stone either?

CCL

 

[Paul-Antwerp]

CCL,

I very much like your real-world example of what might happen in a store. Basically, it is a consumer choosing what he likes most in a limited selection. Most often, the consumer thinks he got the best possible diamond, while his choice was basically limited by the vendor''s selection in what was good-enough according to the vendor. Whether this actually satisfies the desires of the consumer depends on the consumer actually.

A similar thing happens online, surprisingly. Most often, consumers come seeking for advice on a limited selection of their own. Very often, that selection is primarily based on price. The advice offered is based on a number of rejection-tools, regularly in the absence of more info, only on the HCA. As a basis, these rejection-tools are judging brightness as the only factor. Now, this is a great basis for rejection, but it is not complete and not sufficient for the final selection, depending on the consumer''s desires. In a sense, it is a similar selection of ''good enoughs'' with a final choice of one of the ''good enoughs''.

In this, I come to the same conclusion as you, and I will quote you:

"I wonder at which place will the consumer receive a better education and make the most informed decision? That may be a tough one, we all can infer that the vendor selling non super ideals isn''t going to show the consumer a super ideal they don''t sell them. But will the vendor selling super ideals show the consumer the best cheaper non branded stone either?"

This infers that a major choice for a consumer thus is his selection of the vendor. If that selection fits the desires of the consumer, the resulting diamond will fit perfectly. Erring in that selection however will most probably lead to a bad fit, with very often the consumer being unaware.

Live long,

 

[ChunkyCushionLover]

Date: 3/4/2010 5:38:14 AM
Author: Paul-Antwerp
CCL,

I very much like your real-world example of what might happen in a store. Basically, it is a consumer choosing what he likes most in a limited selection. Most often, the consumer thinks he got the best possible diamond, while his choice was basically limited by the vendor's selection in what was good-enough according to the vendor. Whether this actually satisfies the desires of the consumer depends on the consumer actually.

A similar thing happens online, surprisingly. Most often, consumers come seeking for advice on a limited selection of their own. Very often, that selection is primarily based on price. The advice offered is based on a number of rejection-tools, regularly in the absence of more info, only on the HCA. As a basis, these rejection-tools are judging brightness as the only factor. Now, this is a great basis for rejection, but it is not complete and not sufficient for the final selection, depending on the consumer's desires. In a sense, it is a similar selection of 'good enoughs' with a final choice of one of the 'good enoughs'.

In this, I come to the same conclusion as you, and I will quote you:

'I wonder at which place will the consumer receive a better education and make the most informed decision? That may be a tough one, we all can infer that the vendor selling non super ideals isn't going to show the consumer a super ideal they don't sell them. But will the vendor selling super ideals show the consumer the best cheaper non branded stone either?'

This infers that a major choice for a consumer thus is his selection of the vendor. If that selection fits the desires of the consumer, the resulting diamond will fit perfectly. Erring in that selection however will most probably lead to a bad fit, with very often the consumer being unaware.

Live long,

Dear Paul,

I don't agree that HCA is only judging brightness. It also gives scores for fire, scintillation, light return and spread. How well it actually judges the other criteria is a matter of debate and searching for supporting information on pricescope is in my opinion difficult and beyond the scope of these forums.

Spread can be calculated readily, we have a decent handle on leakage and light return from rejection tools(ASET idealscope etc.), and this leaves scintillation and fire.

I started a thread on optimzing fire in the modern RB here https://www.pricescope.com/community/threads/optimizing-fire-in-the-modern-rb-fiery-ideal-cut-fic-how-far-can-we-go-without-serious-detracting.134805/ and really it generated more questions than it did answers.

In my limited diamond education and experience (under a year) I can draw from that thread the following about fire and I would welcome your thoughts and corrections:

1) In a modern Near Tolk Round Brilliants the area of greatest fire potential is in a ring near the edges of the table encompassing the lower girdle facets (see firescope images in the other thread). While ETAS or DETAS and firescope images are not a recognized and universally accepted metric for fire I feel it is fair to show which region of the diamond has the potential to show the most intense fire. Even if firescope images were universally accepted the frequency of events, distribution, duration and size are four important aspects of fire which make it even more difficult to judge this characteristic as we would like to do.

2) In a stone with shorter LGFs and LGF angles very close to that of the pavillion mains (with the appearance similar to an OEC) the virtual facets under the table can be much larger and can encompass the mains and the LGFS with the potential for large flashes of fire and great dispersion from this region under the table.

I have great difficulty comparing the intensity of fire of a near tolk RB versus that of modern OEC.
I have equal difficultly quantifying and comparing intensity of fire differences between an FIC and a TIC.

I can see the size and shape of the flash and notice the differences. While we could use a video of the two diamonds side by side under various filters as GOG does, these comparisons are very limited on pricescope and confined to one vendor who provides this kind of education.

If the use of rejection tools like HCA and Idealscope is not enough than what do you suggest?

I put forth the following question:

"Is choosing the right dealer enough if that dealer can't explain with visual evidence the differences in scintillation and fire in ideal cut diamonds?."
How will they help the consumer make the choice between:

i) TIC and FIC?
ii) Between an Infinity HA Round versus another branded HA?
iii) A 54% table AGS000 versus and 59% table AGS 000,
iv) Between a near HA with no leakage seen on an idealscope, versus a branded H&A?"

Regards,
CCL

 

[Paul-Antwerp]

CCL,

Very good questions and a very thorough reply, I must say.

May I take some time to answer, please? Doing so in a hurry would be disrespectful to the completeness of your questions.

Live long,

 

[ChunkyCushionLover]

Date: 3/5/2010 10:24:22 AM
Author: Paul-Antwerp
CCL,

Very good questions and a very thorough reply, I must say.

May I take some time to answer, please? Doing so in a hurry would be disrespectful to the completeness of your questions.

Live long,

Of course, your time and effort is always appreciated no matter how long it takes for a reply.
I was hoping you would respond in my optimizing FIC thread, but here is just as good.
I subscribed to you so I will get an email when you reply so that I don't miss it.

 

[Regular Guy]

Date: 3/5/2010 10:44:37 AM
Author: ChunkyCushionLover
I was hoping you would respond in my optimizing FIC thread, but here is just as good.

The search function on Pricescope has some good features. You can determine that when Paul is writing, and mentions FIC, this comes up mostly 8 times.

The suggestion is that there are reasons he would not have engaged an FIC thread, given the spurious existence of the FIC.

I like this discussion back a little over 3 years ago, personally. Then again, I was in it, too.

 

[ChunkyCushionLover]

Date: 3/5/2010 11:19:13 AM
Author: Regular Guy

Date: 3/5/2010 10:44:37 AM
Author: ChunkyCushionLover
I was hoping you would respond in my optimizing FIC thread, but here is just as good.

The search function on Pricescope has some good features. You can determine that when Paul is writing, and mentions FIC, this comes up mostly 8 times.

The suggestion is that there are reasons he would not have engaged an FIC thread, given the spurious existence of the FIC.

I like this discussion back a little over 3 years ago, personally. Then again, I was in it, too.

Thanks Regular Guy. I have distilled what I feel are the three main viewpoints below:


Garry H - A well cut FIC has maybe 3-5% less brightness than a TIC - so there is not a huge amount of difference in the overall brightness.

The extra fire should be just percieved in spot lights where there is a lot of fire - but the scintillation / rapidity of sprkle is noticeable when side by side comp's are done.

https://www.pricescope.com/community/threads/1-01-k.52723/

5-10 smaller more frequent flashes compared to 3-5 much bigger flashes. but maybe only 5% more fire in total.

I am making a graphic from http://www.gemology.ru/cut/english/podrobno_1.htm that shares the same scale that i hope will help explain it better
The differences are subtle - not super strong.

https://www.pricescope.com/community/threads/1-01-k.52723/page-2

Paul Antwerp - It is very clear now.

BIC (see example above) has Excellent Fire.
TIC (see example above) has Excellent Fire
FIC logically has Excellent Fire

Deduction, any IC has Excellent Fire.

https://www.pricescope.com/community/threads/wondering-while-looking-at-hca-results.53051/

It is one of my regular discussions with Garry Holloway, where I take the position that FIC does not exist. I think that it is one of these 'old adagios' of the trade that somehow survives.

https://www.pricescope.com/community/threads/canadian-buying-a-diamond-from-the-us-please-help-me-pick-one-of-these-two.106126/

Karl K - I on the other hand take Garry's side because I have seen it with my own eyes.
The difference is not huge however. It is a valid way of cutting a high performance diamond.
If you want an increase in fire the shorter lgf% of a "transitional" or oec make a far greater difference than a tic to fic crown height.

https://www.pricescope.com/community/threads/canadian-buying-a-diamond-from-the-us-please-help-me-pick-one-of-these-two.106126/

Is there more to it? It also seems at the moment that the tradeoff in spread and brightness also precludes stones moving further away from any of the ideal cuts like even steeper crown >36 like the two stones I posted in this thread https://www.pricescope.com/community/threads/optimizing-fire-in-the-modern-rb-fiery-ideal-cut-fic-how-far-can-we-go-without-serious-detracting.134805/ from the Octonus MSS.

 

[Dancing Fire]

call it whatever,but i''m just one of those person whom prefers a small table (54-55%) with a tall crown (15.3-15.7%)

now,with that said...my one of my wife''s ring with specs of 56% table,15% crown height and 80% LGF.

 

[Paul-Antwerp]

Date: 3/5/2010 10:14:19 AM
Author: ChunkyCushionLover

Date: 3/4/2010 5:38:14 AM
Author: Paul-Antwerp
CCL,

I very much like your real-world example of what might happen in a store. Basically, it is a consumer choosing what he likes most in a limited selection. Most often, the consumer thinks he got the best possible diamond, while his choice was basically limited by the vendor''s selection in what was good-enough according to the vendor. Whether this actually satisfies the desires of the consumer depends on the consumer actually.

A similar thing happens online, surprisingly. Most often, consumers come seeking for advice on a limited selection of their own. Very often, that selection is primarily based on price. The advice offered is based on a number of rejection-tools, regularly in the absence of more info, only on the HCA. As a basis, these rejection-tools are judging brightness as the only factor. Now, this is a great basis for rejection, but it is not complete and not sufficient for the final selection, depending on the consumer''s desires. In a sense, it is a similar selection of ''good enoughs'' with a final choice of one of the ''good enoughs''.

In this, I come to the same conclusion as you, and I will quote you:

''I wonder at which place will the consumer receive a better education and make the most informed decision? That may be a tough one, we all can infer that the vendor selling non super ideals isn''t going to show the consumer a super ideal they don''t sell them. But will the vendor selling super ideals show the consumer the best cheaper non branded stone either?''

This infers that a major choice for a consumer thus is his selection of the vendor. If that selection fits the desires of the consumer, the resulting diamond will fit perfectly. Erring in that selection however will most probably lead to a bad fit, with very often the consumer being unaware.

Live long,

Dear Paul,

I don''t agree that HCA is only judging brightness. It also gives scores for fire, scintillation, light return and spread. How well it actually judges the other criteria is a matter of debate and searching for supporting information on pricescope is in my opinion difficult and beyond the scope of these forums.

Spread can be calculated readily, we have a decent handle on leakage and light return from rejection tools(ASET idealscope etc.), and this leaves scintillation and fire.

I started a thread on optimzing fire in the modern RB here https://www.pricescope.com/community/threads/optimizing-fire-in-the-modern-rb-fiery-ideal-cut-fic-how-far-can-we-go-without-serious-detracting.134805/ and really it generated more questions than it did answers.

In my limited diamond education and experience (under a year) I can draw from that thread the following about fire and I would welcome your thoughts and corrections:

1) In a modern Near Tolk Round Brilliants the area of greatest fire potential is in a ring near the edges of the table encompassing the lower girdle facets (see firescope images in the other thread). While ETAS or DETAS and firescope images are not a recognized and universally accepted metric for fire I feel it is fair to show which region of the diamond has the potential to show the most intense fire. Even if firescope images were universally accepted the frequency of events, distribution, duration and size are four important aspects of fire which make it even more difficult to judge this characteristic as we would like to do.

2) In a stone with shorter LGFs and LGF angles very close to that of the pavillion mains (with the appearance similar to an OEC) the virtual facets under the table can be much larger and can encompass the mains and the LGFS with the potential for large flashes of fire and great dispersion from this region under the table.

I have great difficulty comparing the intensity of fire of a near tolk RB versus that of modern OEC.
I have equal difficultly quantifying and comparing intensity of fire differences between an FIC and a TIC.

I can see the size and shape of the flash and notice the differences. While we could use a video of the two diamonds side by side under various filters as GOG does, these comparisons are very limited on pricescope and confined to one vendor who provides this kind of education.

If the use of rejection tools like HCA and Idealscope is not enough than what do you suggest?

I put forth the following question:

''Is choosing the right dealer enough if that dealer can''t explain with visual evidence the differences in scintillation and fire in ideal cut diamonds?.''
How will they help the consumer make the choice between:

i) TIC and FIC?
ii) Between an Infinity HA Round versus another branded HA?
iii) A 54% table AGS000 versus and 59% table AGS 000,
iv) Between a near HA with no leakage seen on an idealscope, versus a branded H&A?''

Regards,
CCL

CCL,

Your post contains a lot of topics. Unfortunately, I am not able to give you the final answer to many of the questions. Instead, I will try to highlight the limitations of our current knowledge.

First, your disagreement, in your words "I don''t agree that HCA is only judging brightness. It also gives scores for fire, scintillation, light return and spread."

Well, actually, the HCA gives scores on light return, fire, scintillation and spread. But what are these scores based upon? Spread, I agree, is probably an easy arythmetic function. Scintillation however is impossible to predict, based upon the few average numbers entered into the HCA. As for light return, equal to potential brightness according to me, I think it is the strongest predictor in the HCA. Finally, fire is the difficult factor. If one thinks that fire is the enemy of brightness, then I wonder how the few numbers entered into the HCA can result in a score for fire. If one agrees with my thinking that brightness is the friend of fire, the potential fire-score is in many ways a resultant of the potential light return (brightness) score. But that notion then again is difficult to combine with the distinction between FIC, TIC and BIC.

Most important in the above paragraph is that I consider fire to be the friend of brightness. Let me try to explain. When evaluating a diamond, there are many factors, the light environment, the diamond itself, the moving of the diamond and the observer. In the end, the important matter is whether an observer as a result of these factors observes sparkles returning from the diamond. Brightness in this is the measure of all the sparkles observed, whether fiery or not. Since theoretically almost all light rays exiting a diamond are dispersed to some extent, it depends upon the interaction diamond-observer whether white or coloured light is observed. Potential brightness is the potential light return, considering the fact that there are an infinite number of light environments.

In this way of thinking, where the potential to return light to the eyes of the observer is more important, the potential fire is actually related to potential brightness, with the differing factors being the light environment and the observer. Fire in that sense is a subsection of brightness and it can be observed in all the potentially bright areas of the stone.

In that regard, when looking at an OEC, the fact that it can exhibit larges flashes of fire is related to the stone having larger virtual facets in some areas of the stone. In such a stone, the larger flash needs to be offset by a reduced probability of that facet actually returning light to the observer. Considering that trade-of, it is difficult to say which stone has the highest potential fire, and most probably, taste of the observer will become a defining factor then.

All this leads me to the point that most current assessment-methods are based upon a judgment of potential brightness only. As an exception, the AGS cut-grade-determination contains a minor factor, judging potential fire. But most importantly, no assessment-method judges scintillation for now.

This actually is the limitation to be aware of. Some are trying to show and judge scintillation online with virtual models and virtual movies. But because of the size of the diamond on the screen, I find it impossible to use. As for actual comparison-videos, no matter how good the attempt, they do not grasp the differences, observable in real life. The usage of filters may highlight certain aspects, but it takes us further away from the actual observation of the diamond.

That limitation is also the limitation of advice on PS. We can help consumers through a number of rejection-decisions, but the final selection is impossible. For that final selection, the consumer either has to guess or arrange for certain stones to be compared in real life. And in this selection, a good retailer is a consumer''s best friend.

Live long,

 

[Karl_K]

I mildly disagree with some of Paul's points and some I think he is on the right track but for the wrong reasons in my opinion, others he is spot on.

The primary fire difference between an oec, bic, tic, fic is not which has more or better fire but which lighting conditions fire is observed.
FIC and OEC will show fire in more lighting conditions than a bic or tic.
In the lighting conditions most conductive to fire they all have the potential for excellent fire but with different looks.
Video is an excellent tool to show the different looks even though it is not perfect.

As far as scintillation goes the best way to judge it is to understand virtual facets and the only way to see it online is video, either real or virtual.

It is possible to optimize for both fire and brightness but you have to make a comprimise eventually towards one or the other, not in amount but in the amount of lighting conditions each is the primary return.

I do agree that brightness potential is the best use of the HCA.
IS and ASET are pretty useless at predicting scintillation because they do not clearly show all virtual facets.
ASET has a fundamental defect in that 2 virtual facets can be red but they fire at different times.
It does not show or take into account phase based contrast where virtual facets being out of sync with each other creates contrast.

Where I strongly disagree, is in my opinion that the tools can be used for final online selection then verified by the eyes when received.
Do the tools get you to 100% no they don't, but they get you far enough to select one to see in person.
That has been proven time and time again for years on PS.
Is a good vendor a part of that, sure is.
It is like putting together a puzzle and each bit of information is a piece of the puzzle that creates the whole which is the confidence to say that one and buy it.

 

[soontomarry2]

If I''m looking at a stone that has a crown angle at the top end of the acceptable ideal range, 34.8. Is it generally best to match it with a pavilion angle that is slightly higher or lower than the ideal value of 40.75? I ask because unfortunately, a lot of diamonds I''m looking at have crown angles of 34.7, 34.8, and 34.9, way higher than the ideal 34.5.

 

[ChunkyCushionLover]

Date: 3/8/2010 10:58:20 AM
Author: soontomarry2
If I''m looking at a stone that has a crown angle at the top end of the acceptable ideal range, 34.8. Is it generally best to match it with a pavilion angle that is slightly higher or lower than the ideal value of 40.75? I ask because unfortunately, a lot of diamonds I''m looking at have crown angles of 34.7, 34.8, and 34.9, way higher than the ideal 34.5.

Soontomarry2,


Despite the conversation and the merits of using HCA, for your purposes you will be well served by using the HCA to answer those basic queries. It is adequate for identifying stones within the Ideal cut ranges and complimentary crown/angle combinations.

You don''t need to be fixed at a crown angle of 34.5 many combinations are suitable see this chart https://www.pricescope.com/wiki/diamonds/holloway-cut-advisor/.

 

[Lorelei]

Date: 3/8/2010 11:23:19 AM

Date: 3/8/2010 10:58:20 AM
Author: soontomarry2
If I'm looking at a stone that has a crown angle at the top end of the acceptable ideal range, 34.8. Is it generally best to match it with a pavilion angle that is slightly higher or lower than the ideal value of 40.75? I ask because unfortunately, a lot of diamonds I'm looking at have crown angles of 34.7, 34.8, and 34.9, way higher than the ideal 34.5.

With a 34.8 degree crown, a pavilion angle of around 40.6 - 40.8 degrees could work well, maybe even 41 degrees if the overall cutting is tight but your best bet is to always confirm with images such as Idealscope, as various factors can affect the efficiency of these angles that can't be seen without images. Because a set of theoretical numbers might at face value seem to work well, images are essential in order to prove they do.

Also as crown and pavilion angles have an inverse relationship, caution is needed if the angles appear to balance but swing out a long way in either direction. For example, you could have a diamond which has scores reasonably on the HCA with a shallower crown angle but actually has a steep pavilion angle, then other undesirable issues can come into play, so try to keep pavilion angles where possible between 40.6 - 41 degrees.
And of course the proof of the pudding is always seeing the stone in person, so you can compare it to others in order to decide if its the right one for you.

 

[Paul-Antwerp]

Date: 3/8/2010 9:11:26 AM
Author: Karl_K
I mildly disagree with some of Paul''s points and some I think he is on the right track but for the wrong reasons in my opinion, others he is spot on.

...
Where I strongly disagree, is in my opinion that the tools can be used for final online selection then verified by the eyes when received.
Do the tools get you to 100% no they don''t, but they get you far enough to select one to see in person.
That has been proven time and time again for years on PS.
Is a good vendor a part of that, sure is.
It is like putting together a puzzle and each bit of information is a piece of the puzzle that creates the whole which is the confidence to say that one and buy it.

Hi Karl,

Let me consider our strong disagreement first.

So, basically, you said that the only way to judge scintillation is video, either real or virtual. I personally cannot judge scintillation in that way, but let us assume that you can.

Still, with video not being something generally offered by vendors, you are saying that the available tools can be used for final online selection. Thus, in the absence of video, this selection is not based on any assessment of scintillation. That does not sound logical to me. In any case, it shows that you are selecting without having all the pieces of the puzzle.

It seems as if you are saying that all stones that passed the rejection-tests are basically the same. Select one and the experience on PS has proven that most consumers will like that stone.

I am sorry, but that PS-experience does not prove your point. In the few cases that PS-consumers have actually compared stones, that on all the tests and probably on reputation too were identical, they could indeed observe differences and express preferences.

If you are saying that all stones passing cut-grade, HCA, IS and ASET (possibly H&A) are the same, I indeed most strongly disagree with you.

If however you are saying that all stones passing these tests are ''good enough'' for the average unprepared consumer, who will never know about the potential differences, you might well be right. Does that mean that at a certain level, ignorance becomes bliss?

Live long,

 

[Karl_K]

Date: 3/8/2010 11:39:56 AM
Author: Paul-Antwerp

So, basically, you said that the only way to judge scintillation is video, either real or virtual. I personally cannot judge scintillation in that way, but let us assume that you can.

it is the only way to show it, not judge it.

Still, with video not being something generally offered by vendors, you are saying that the available tools can be used for final online selection. Thus, in the absence of video, this selection is not based on any assessment of scintillation.

a diamond that passes all the tests is going to have excellent scintillation. Not the same but excellent none the less. Fancies its more of an issue


It seems as if you are saying that all stones that passed the rejection-tests are basically the same.
they have different personalities which is discussed often so no they are not all the same.


Select one and the experience on PS has proven that most consumers will like that stone.

true


I am sorry, but that PS-experience does not prove your point. In the few cases that PS-consumers have actually compared stones, that on all the tests and probably on reputation too were identical, they could indeed observe differences and express preferences.

of course there are differences in personality. Even from one of your diamonds to the next if you look hard enough and yours are some of the most consistent in the world.


If you are saying that all stones passing cut-grade, HCA, IS and ASET (possibly H&A) are the same, I indeed most strongly disagree with you.
that is not what I am saying at all. What I am saying is that any diamond that passes all the test is worth an in person look.

If however you are saying that all stones passing these tests are 'good enough' for the average unprepared consumer, who will never know about the potential differences, you might well be right. Does that mean that at a certain level, ignorance becomes bliss?

any diamond that passes all the tests will be among the best cut diamonds in the world.
Making a choice based on a ton of criteria is not ignorance
I will give you that there may be a diamond out there they like the personality of better than the one selected, that weakness will always exist when buying online and even in a B&M store.


Live long,

 

[Paul-Antwerp]

Karl,

Let me put your reasoning in bullet-points:

- Videos can show scintillation, but you cannot judge it based on video.
- A diamond passing all the rejection-tests automatically has excellent scintillation.
- The difference remaining between diamonds passing the tests are differences in personality.
- All passing are among the best cut diamonds in the world.
- The combination of all the rejection-tests are a ton of criteria.

I probably agree with your first point about not being able to judge scintillation by video. I for sure cannot.

Knowing this and since no rejection-tool effectively assesses scintillation, I find the second point the weirdest ever. So, excellent scintillation is an automatic given if the tests not testing it are OK? This obviously depends on how you define ''excellent''. And I like that you stress this is not the case for fancy shapes. Still, also in rounds, you are making an incorrect presumption.

Your third point is an automatic consequence of your second point. Since you do not accept that there are observable differences in performance, you need to call the differences personality-issues. That is too bad. There are big differences in scintillation and these differences also have an effect on observable fire. So, I strongly disagree, the remaining differences are not personality-issues only.

As for your fourth point, all passing are among the best cut diamonds in the world, it is a bit of a blanket-statement, that can mean anything. Yes, I agree, all stones passing all the available tests are better than average, simply because of the tests. But whether they automatically are among the best entirely depends upon the definition of the best. I would say that they are ''good enough'' to consider, like you also mentioned in another sentence.

Finally, your last point is very important. Yes, all the tests together are a lot of criteria, cut-grade, HCA, IS, ASET, possibly H&A. But let us consider them in a critical way. Cut-grade, HCA, IS and ASET mainly assess the same, brightness. H&A adds contrast-brightness, although some would argue that the same can be assessed in IS and/or ASET. In that way, the ton of criteria is reduced to those criteria all basically measuring the same. And for the very important differing factors of scintillation and fire, these tests are not sufficient.

My point thus is that there definitely are differences in performance beyond the limitations of all rejection-tools combined. In our experience, it has been proven regularly by the few consumers who actually compared stones having passed all the test. They did not observe a difference in personality, since they all expressed the same preference. At that point, it becomes a difference in performance, not assessed by the rejection-tests.

Live long,

 

[Karl_K]

Date: 3/9/2010 5:42:03 AM
Author: Paul-Antwerp

Knowing this and since no rejection-tool effectively assesses scintillation, I find the second point the weirdest ever. So, excellent scintillation is an automatic given if the tests not testing it are OK? This obviously depends on how you define 'excellent'. And I like that you stress this is not the case for fancy shapes. Still, also in rounds, you are making an incorrect presumption.

RB diamonds have the facet locations tied to the design fancies do not.
A diamond that passes hca/ASET/IS/H&A is going to have all the facets in the right places to produce excellent scintillation.
The personality of the scintillation changes.

What criteria would you use to grade scintillation?
An OEC and a 85% lgf tolk both can have excellent scintillation yet the appearance of the scintillation will be hugely different in any lighting.
Even deciding on the right lighting to grade scintillation is an impossible task, it will look extremely different in different lighting as different virtual facets are active.

 

[Rockdiamond]

Date: 3/3/2010 12:04:55 PM
Author: ChunkyCushionLover

Date: 3/3/2010 6:03:29 AM
Author: Paul-Antwerp

Date: 3/2/2010 9:22:48 PM
Author:soontomarry2
I looking at a particular stone with these angles:

Crown Angle: 33.5
Pavilion angle: 40.8
Depth: 59.6%
Table: 59%
Pavilion Depth: 40.8%

Does the table seem large and the crown angle small? Interesting, it does well on the Holloway Cut Adviser and it is rated as GIA excellent.

In person, the stone looked great, but maybe one with more ideal cuts would look even better?

The stone passes the first rejection-test of HCA, and you also like it, when viewing it in person, so there is a good chance of it passing the next rejection-tests (IS, ASET, ...) too.

But nobody but you can answer your highlighted question. Only you can compare and assess whether you appreciate a better-cut stone and if so, if you consider its probable premium appropriate.

Live long,

''Probable Premium Appropriate'' PPA that should be a new term used often here. This should be the new Pricescope FAD!

This is at the heart of why I am extremely positive about stones cut for light performance and super ideal cut diamonds in all shapes, and really pushing for consumers to make an informed choice between these and other diamonds which may have other redeeming qualities.

---------------------------------------------------
Simplifie Example:

Customer walks into a diamond shop of a vendor who doesn''t use modern technology for diamond selection and only sells non branded or non ideal cut diamonds:

Dealer shows them 10 diamonds they are all pretty no surprise, diamonds in jewelry store lights usually are.
Customer being diamond savvy views the diamonds in the window, under a table etc. and then finds now only 3 are pretty to them in different lighting.
Dealer says ''trust my experience and what your eyes see'' and suggests 1 of the three.
Customer purchases that diamond and is confident they chose the most beautiful diamond for them. After all it was the best one out of the 10 and the ''expert'' dealer said so.

Now customer walks down the street and looks at some branded ideal cut H&A diamonds with all the reflector tests available, priced 10 - 20% more and says wow my ''most beautiful'' diamond isn''t as beautiful as these ones I wish I had paid the premium.

or

The customer looks at the branded diamonds and says well these are beautiful too but not 20% more beautiful than what I bought I am happy with my decision.
-----------------------------------------------------

I wonder at which place will the consumer receive a better education and make the most informed decision? That may be a tough one, we all can infer that the vendor selling non super ideals isn''t going to show the consumer a super ideal they don''t sell them. But will the vendor selling super ideals show the consumer the best cheaper non branded stone either?

CCL

Hi ccl,
I was just wondering why the word "expert" has quotation marks around it.
Do you not believe that there are actually sellers with a lot of experience that are considered true expert by the trade at large?
Then, of course I''d mention that many of the true experts in the field do NOT agree with some of the principles you seem to take as some sort of "written in stone" facts.

I''m not disagreeing with the use of HCA or ASET- rather that the majority of sellers do not use these tools- and that a percentage of the sellers I''m referring to are, in fact, experts.
There are different ways to educate people about how to select a diamond based on it''s cut.

 

[ChunkyCushionLover]

Date: 3/9/2010 12:49:33 PM
Author: Rockdiamond

Date: 3/3/2010 12:04:55 PM
Author: ChunkyCushionLover

Date: 3/3/2010 6:03:29 AM
Author: Paul-Antwerp

Date: 3/2/2010 9:22:48 PM
Author:soontomarry2
I looking at a particular stone with these angles:

Crown Angle: 33.5
Pavilion angle: 40.8
Depth: 59.6%
Table: 59%
Pavilion Depth: 40.8%

Does the table seem large and the crown angle small? Interesting, it does well on the Holloway Cut Adviser and it is rated as GIA excellent.

In person, the stone looked great, but maybe one with more ideal cuts would look even better?

The stone passes the first rejection-test of HCA, and you also like it, when viewing it in person, so there is a good chance of it passing the next rejection-tests (IS, ASET, ...) too.

But nobody but you can answer your highlighted question. Only you can compare and assess whether you appreciate a better-cut stone and if so, if you consider its probable premium appropriate.

Live long,

'Probable Premium Appropriate' PPA that should be a new term used often here. This should be the new Pricescope FAD!

This is at the heart of why I am extremely positive about stones cut for light performance and super ideal cut diamonds in all shapes, and really pushing for consumers to make an informed choice between these and other diamonds which may have other redeeming qualities.

---------------------------------------------------
Simplifie Example:

Customer walks into a diamond shop of a vendor who doesn't use modern technology for diamond selection and only sells non branded or non ideal cut diamonds:

Dealer shows them 10 diamonds they are all pretty no surprise, diamonds in jewelry store lights usually are.
Customer being diamond savvy views the diamonds in the window, under a table etc. and then finds now only 3 are pretty to them in different lighting.
Dealer says 'trust my experience and what your eyes see' and suggests 1 of the three.
Customer purchases that diamond and is confident they chose the most beautiful diamond for them. After all it was the best one out of the 10 and the 'expert' dealer said so.

Now customer walks down the street and looks at some branded ideal cut H&A diamonds with all the reflector tests available, priced 10 - 20% more and says wow my 'most beautiful' diamond isn't as beautiful as these ones I wish I had paid the premium.

or

The customer looks at the branded diamonds and says well these are beautiful too but not 20% more beautiful than what I bought I am happy with my decision.
-----------------------------------------------------

I wonder at which place will the consumer receive a better education and make the most informed decision? That may be a tough one, we all can infer that the vendor selling non super ideals isn't going to show the consumer a super ideal they don't sell them. But will the vendor selling super ideals show the consumer the best cheaper non branded stone either?

CCL

Hi ccl,
I was just wondering why the word 'expert' has quotation marks around it.
Do you not believe that there are actually sellers with a lot of experience that are considered true expert by the trade at large?
Then, of course I'd mention that many of the true experts in the field do NOT agree with some of the principles you seem to take as some sort of 'written in stone' facts.

I'm not disagreeing with the use of HCA or ASET- rather that the majority of sellers do not use these tools- and that a percentage of the sellers I'm referring to are, in fact, experts.
There are different ways to educate people about how to select a diamond based on it's cut.

David,

As I gain more experience on Pricescope I am learning what does and doesn't work here, what posters take exception, the hierarchy and reputation levels of the posters here, the styles and the perspective and different individuals motivation(s) for posting here. I am slowly learning which arguments are worth participating in and which ones should be left to myself. You are quite correct when you say that some of the commonly held positions on Pricescope are not written in stone nor well respected by the trade outside of Pricescope.

In most cases for me here now, no argument is worth having, especially with any dedicated poster like yourself. From the outside looking in whether it be novice or experienced, very few people see either of our sides on issues or respect either of our arguments in threads. All they often see is two posters who disrespect each other and that this is neither educational nor in the spirit of these forums. Further I will certainly not endear myself to the experts who will be referees for my future articles by continuing to isolate myself and put down other poster's opinions.

Mark Twain has been attriibuted as saying "http:///It is better to remain silent and be thought a fool, than to speak and remove all doubt."http://it/

I am focussing my efforts on writing articles on cushion cut diamonds at the moment to add to the knowledge base at Pricescope as I feel can better educate in that format than having an argument with you in any thread.

Despite appearances to the contrary I have tried my best to learn from you and to a small extent have done so especially in the area of colored diamonds. In future I am going to make an extra effort to understand the content and support you provide for your opinions, if we disagree on an issue I will probably not mention it and I most certainly will not participate in any inflammatory debates with you.

Regards,
CCL

 

[Rockdiamond]

ccl- my position has ALWAYS been that insulting someone merely because they prefer different types of cut in a diamond is totally uncalled for- and I''m glad to hear you agree ( if you actually do)

Still, even if a particular poster has been insulting to another, that does not need erase the value of the discussion.

In the interest of fairness, can you see my point that that parts of your post expressing disdain for people who may run jewelry stores not using "modern technology" is overly general?
I feel it was worded in such a manner as to imply that the choice not to use what you call "modern technology" would unfairly, and arbitrarily bring into question a seller''s general knowledge of diamonds, and diamond selection.

Not to argue, but to explain why the use of overly general statements that can be seen as insulting does nothing to actually forward the discussion.

 

[Paul-Antwerp]

David,

There was nothing insulting in CCL putting the word expert in quotation-marks. It is a common way of demonstrating that one uses a word, while one does not necessarily automatically agree that that word applies.

As for your reasoning, I know a lot of professionals here in Antwerp with the reputation of being true diamond-experts. Most probably, here in the district, I am not one with the reputation of an expert. More realistic is to consider that my reputation is more that of a ''freak'' or a ''lunatic'', a cutnut, if you want.

Nevertheless, I have regularly helped out these ''experts'' in getting them the desired cut-quality.

The point is: Those who you call experts, may well have earned that reputation in the past, a reputation bestowed upon them by a community who considered the experts as better. But if these experts today do not know or refuse the latest technology and science (yes, written in stone), they are indeed forfeiting their right to the epitheton of expert.

Live long,

 

[Rockdiamond]

Paul, if I heard someone use such charachterizations of you ( freak, lunatic..) I would also be bothered by it.
ccl has frequently expressed disdain for jewelers simply because they may not see things as he does.
I still feel that the quotations were used in an insulting manner.

In terms of experts refusing science, what science specifically are you referring to?

 

[Paul-Antwerp]

GIA''s and AGS''s cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only.

Live long,

 

[Dreamer_D]

Based on my personal experience visit-ng jewelry stores, and granted it is not universal, I would also put the term "experts" in quotations to refer to most proprietors. Some seemed like experts, surely, but the majority did not. And it had nothing to do with using or not using modern technology. It had to do with their apparent ignorance of simple matters, or, if not ignorance, then blatant misleading of customers. I think that the jewelers I have met have been experts in sales, but certainly not in diamonds or in customer service. If that is overly general, so be it. I am a "just" a consumer and that''s how I see things

.

 

[Karl_K]

When it comes to experts in the diamond/jewelery industry you will quickly find that there is no one that is an expert in all facets of the industry.
Each may have an area or 2 or 3 that they know a lot about but it is impossible to be an expert in them all.
You will find someone who is the top person in their area who knows next to nothing about another area.
I do kinda get a laugh about people who think they are "the" expert when it comes to the industry but there are several people I deeply respect in their area of expertness.