ASETs and fancy cuts

[MelisendeDiamonds]

here is light which enters the diamond from right below the 45 deg points.

I am still not certain what you mean by just below the 45 degree point.

Which colored arrow is closest to what you are referring to?, if its the grey arrows that is negative numbers like -5 or -10.
The white arrows are like -0 on one and -45 or so on the other.

If its the green arrow that is just below +45. If its the red its above <+45.
Are you talking about rays that are pointed to by the grey arrows?

Oops, sorry for the confusion (my bad). Of course I meant slightly below the 0 (e.g. -3 to -5).

Diagem,

I do apologize I didn't mean to imply you photoshopped that photo above, I am now starting to understand where that diamond is drawing light from and the ASET image. It would have been much easier with if you attached the .gem file but I understand if you wish to protect the privacy of your proprietary design.

So your question is about AGSL cut grading and the AGS-PGS and not about ASET, as you are probably aware they use a numerical algo not a visual inspection of the ASET 30 map.

Did they give you a template to be used in AGS-PGS for cushions? Or did you submit it to the lab for LP grading?
I see two obstacles to it getting 0 for light performance. Both brightness and leakage. You question is about the leakage one and arguing that -3 to -5 is not as bad as -90 or -45 and that the leakage deduction should be scaled? Much like the Red/Green brightness deduction.
Am I following you correctly?

 

[RADIANTMAN]

Garry - I have an enormous amount of respect for the work that you and the cut group do, specifically because you recognize complexities that other cut grade systems have chosen to ignore rather than to acknowledge and try to account for. But I was truly surprised when you wrote:

"The crushed ice cushion I referred too from the MSS stones has some attraction. However I think the number of people who would choose the stone with the 2 sets of 3 images that you are referring to would be very small if they had other stones to compare in a side by side comparison."

Unless and until you have actually done a real and substantial consumer survey with the side by side comparison, your opinion about what consumers would choose in a side by side comparison without prompting is simply a statement of your personal preference repackaged as something more meaningful. In my opinion, you are wrong and my opinion is every bit as meaningless as yours.

Let me share a true story that illustrates my point. Many years ago, before newfangled round stone cuts were in vogue, my Dad and I were commissioned to create a customized roundstone for a client. We designed the diamond to our customer's specs, but frankly didn't think it was close to as nice as a traditional round. There is no question that it would have "performed" poorly had today's technology been available to test it.

For the hell of it, I showed it side by side with a well cut traditional round to twenty friends, half men half women, none of whom were in the jewelery trade or knew anything about diamonds or jewelry. I expected them all to like the traditional cut better because to me and to my dad, who were used to a certain "look" it was obviously nicer.

Well guess what. of the 12 who could tell the difference, 9 - 75% - liked the new cut better.

Now the survey was not scientific. The lighting conditions varied randomly since I did this in people's living rooms, in restaurants and even in Central Park. The sample is obviously too small for even the 75%-25% preference for the new cut to be statistically meaningful.

But I learned an important lesson that I've never forgotten. And as we develop better and better technology to measure the characteristics of light reflection in diamonds it is an important lesson for us all to remember.

 

[Texas Leaguer]

Garry - I have an enormous amount of respect for the work that you and the cut group do, specifically because you recognize complexities that other cut grade systems have chosen to ignore rather than to acknowledge and try to account for. But I was truly surprised when you wrote:

"The crushed ice cushion I referred too from the MSS stones has some attraction. However I think the number of people who would choose the stone with the 2 sets of 3 images that you are referring to would be very small if they had other stones to compare in a side by side comparison."

Unless and until you have actually done a real and substantial consumer survey with the side by side comparison, your opinion about what consumers would choose in a side by side comparison without prompting is simply a statement of your personal preference repackaged as something more meaningful. In my opinion, you are wrong and my opinion is every bit as meaningless as yours.

Let me share a true story that illustrates my point. Many years ago, before newfangled round stone cuts were in vogue, my Dad and I were commissioned to create a customized roundstone for a client. We designed the diamond to our customer's specs, but frankly didn't think it was close to as nice as a traditional round. There is no question that it would have "performed" poorly had today's technology been available to test it.

For the hell of it, I showed it side by side with a well cut traditional round to twenty friends, half men half women, none of whom were in the jewelery trade or knew anything about diamonds or jewelry. I expected them all to like the traditional cut better because to me and to my dad, who were used to a certain "look" it was obviously nicer.

Well guess what. of the 12 who could tell the difference, 9 - 75% - liked the new cut better.

Now the survey was not scientific. The lighting conditions varied randomly since I did this in people's living rooms, in restaurants and even in Central Park. The sample is obviously too small for even the 75%-25% preference for the new cut to be statistically meaningful.

But I learned an important lesson that I've never forgotten. And as we develop better and better technology to measure the characteristics of light reflection in diamonds it is an important lesson for us all to remember.

Stan,
You make your point well about differences in taste. Not speaking for Garry (he is quite capable of that!) but I do think it is hard for any of us to discuss diamonds and diamond beauty without introducing our own preferences or making observations based upon our own personal experiences working with consumers. Nor is there any reason to completely avoid doing so. But from reading the article Garry posted it appears that it is the specific goal of the cut group to expand the range of options and flavors of diamonds and to give the trade better ways of communicating the various aspects of diamond beauty, and to give consumers better understanding and appreciation of how the various aspects of light performance impact beauty.

I hope you are able to establish a working relationship with the cut group because I think your expertise would be extremely valuable to this effort.

I might add that I feel the same is true of Haroutioun (Melisende Diamonds). I am very impressed with the knowledge and insight being brought forth here.

 

[Rockdiamond]

Bryan- one part of your post made me think about part of why I see what seems like disagreements - I prefer to think of them as discussing fine points.

but I do think it is hard for any of us to discuss diamonds and diamond beauty without introducing our own preferences or making observations based upon our own personal experiences working with consumers. Nor is there any reason to completely avoid doing so.

I think part of what makes this discussion so darn interesting is the differing perspectives we bring, as professionals.
The reason is that we have such different jobs.
I've spent days ( literally) discussing finer points with some of the best cutters in the world.
Some are more generic- they can bend to any cutting style well- but they never create something revolutionary.
That does not demean their work in any way- cutting a "traditional" fancy shape really well is a tremendous skill.
But when we come to cutters that actually create designs that bring something new to the table- by necessity, and or nature, they are incredibly opinionated.
As is Garry. Although he's not a cutter, he's also brought many incredible innovations to the table- requiring the kind of independent thinking bound to come with strongly held opinions.
I respect Garry's opinion tremendously, however my opinion is, in some cases, diametrically opposed.

Bryan- you and I , among others occupy a different position in the food chain.
We have to advise a broad range of consumers.
Do folks ask me my opinion?
All the time.
Do I give it?
Very sparingly if they are looking at two stones which are both photographed well.
We can also make that point about ASET.
What difference does it make to a consumer if I love a stone better? Or say the ASET is "better"
They have to love it.

I wholeheartedly agree with Stan's point about characterizations.
In fact, you could say that such characterizations sparked the latest round of invigorating discussion.

 

[Texas Leaguer]

Bryan- one part of your post made me think about part of why I see what seems like disagreements - I prefer to think of them as discussing fine points.

but I do think it is hard for any of us to discuss diamonds and diamond beauty without introducing our own preferences or making observations based upon our own personal experiences working with consumers. Nor is there any reason to completely avoid doing so.

I think part of what makes this discussion so darn interesting is the differing perspectives we bring, as professionals.
The reason is that we have such different jobs.
I've spent days ( literally) discussing finer points with some of the best cutters in the world.
Some are more generic- they can bend to any cutting style well- but they never create something revolutionary.
That does not demean their work in any way- cutting a "traditional" fancy shape really well is a tremendous skill.
But when we come to cutters that actually create designs that bring something new to the table- by necessity, and or nature, they are incredibly opinionated.
As is Garry. Although he's not a cutter, he's also brought many incredible innovations to the table- requiring the kind of independent thinking bound to come with strongly held opinions.
I respect Garry's opinion tremendously, however my opinion is, in some cases, diametrically opposed.

Bryan- you and I , among others occupy a different position in the food chain.
We have to advise a broad range of consumers.
Do folks ask me my opinion?
All the time.
Do I give it?
Very sparingly if they are looking at two stones which are both photographed well.
We can also make that point about ASET.
What difference does it make to a consumer if I love a stone better? Or say the ASET is "better"
They have to love it.

I wholeheartedly agree with Stan's point about characterizations.
In fact, you could say that such characterizations sparked the latest round of invigorating discussion.

David,
I am not at all surprised that you would pull that one line out of my post as an opportunity to continue your long term campaign against subjectivity and bias. Which is a little bizarre because it seems to me you would prefer for the entirety of diamond evaluation to be completely subjective- a "look at the diamond - do you love it? - nothing else matters" kind of approach.

Ironically, it seems to me you have a great deal to gain from a thorough understanding of tools like ASET. The kind of work that Karl, Yorem, Garry, Serg, Haroutioun, and others are doing (not the least of which is AGSL) could result in new and powerful ways to market fancy cuts to a whole new generation of buyers who A) embrace technology and B) are doing an ever increasing amount of their buying remotely through e-commerce.

I believe with the right understanding and interpretation of ASET and other diagnostic tools, the number of consumers comfortable selecting the right diamonds for their particular tastes will grow substantially. And the low hanging fruit here is, in fact, fancy cut diamonds, which are still the hardest to understand.

The first hurdle a consumer must overcome in order to buy a diamond is to understand the product. The days of selling by means of "trust me, I've seen alot of diamonds and this one is great" or even "trust your eyes, if you think the diamond is beautiful that's all that counts" are receding into the past at an ever increasing rate.

 

[Rockdiamond]

Bryan- its the mixing of subjective and objective that I feel is pejorative towards certain types of cuts. And I am by no means the only one who feels this way. If you read the posts, Stan agrees with me. My "long campaign" is due to the fact that it's been this way since at least 2006.
My "long campaign" may be part of why this is still an active discussion- which may indeed bear fruit.

If you read back a few pages- I am suggesting that we find cutters willing to embrace a different style of cut than AGSL currently supports to broaden the definition of what is considered to be "well cut" in fancy shapes.
Maybe this is part of the reason AGSL has such a minuscule market share- something I'd personally love to see change.

Moreover, peace man
I'm not attacking you or anything you do.

 

[RADIANTMAN]

Bryan - the reason why Garry's comment that projected his own preferences onto "most" consumers surprised me was precisely because that statement seemed inconsistent to me with the extremely measured and objective approach in the terrific Rappaport article I read yesterday on my way home from work.

It is no secret that Garry doesn't like what he considers "crushed ice" in colorless diamonds. But the larger flashes characteristic of round brilliants are not better or worse than the smaller flashes characteristic of well cut radiants. They are simply different as are the broader flashes of a well cut step cut. Some folks will prefer one style, others another and while science can explain why each style appears as it does and can help consumers understand what they are seeing, it can't "rank" them in some kind of gemological order.

I have often encountered consumers who start the conversation saying "I don't want "crushed ice" who then fall in love with a well cut radiant because the diamonds look very different than the discussions about "crushed ice" led them to believe they would look like.

Obviously we all have personal preferences and all I am suggesting is that it's important to at least try to separate those preferences from our scientific analysis. I like the way my original radiants reflect light far better than the way princesses reflect light. So, in my experience, do many people. Perhaps most. In my experience it is most when they make the comparison side by side.

Obviously my preference (and my belief that most people share it) involves more than a little self interest, but I have never said (and would never say) that radiants are gemologically superior to princesses. I tell folks that the two styles reflect light differently, they're supposed to, and they should look at both and choose the one that they like best.

This doesn't mean that I think beauty is completely subjective and there's no such thing as "better" and "worse" cuts within the same style. Of course I do. After all, I am very much in the fine cut businesses and that means I believe there is a very real and substantial difference between my Original Radiants and most generics that is readily apparent when the diamonds are viewed side by side (I hope I didn't break any rules there!).

At the end of the day we're not really disagreeing about much here - just about whether we should choose our language a little more carefully so consumers are clear about when we are describing science, and when we are describing our personal tastes. And I would welcome the opportunity to work with Garry and the cut group since I think the work that they've done is absolutely amazing - by far the most serious effort I know of to truly understand diamond optics.

 

[diagem]

Diagem,

So your question is about AGSL cut grading and the AGS-PGS and not about ASET, as you are probably aware they use a numerical algo not a visual inspection of the ASET 30 map.

Did they give you a template to be used in AGS-PGS for cushions? Or did you submit it to the lab for LP grading?
I see two obstacles to it getting 0 for light performance. Both brightness and leakage. You question is about the leakage one and arguing that -3 to -5 is not as bad as -90 or -45 and that the leakage deduction should be scaled? Much like the Red/Green brightness deduction.
Am I following you correctly?

My question or story is actually to show that not all what is identified as "leakage" has the same even visual result. Sure leakage on a lopsided/off-balanced cut can be a big negative on any Diamond cut appearance but designed symmetrical leakage can have their advantage if taken into account on a specific design (like the example of the Cushion I posted). This specific design was analyzed by AGSL on its 3D file, it got deductions as you estimated very well both for brightness 0.60 & leakage 0.31. (Based on memory as I am out of the office). A cumulative deducted score of 0.91 (e.g. LP score of 1).
It's a pity as this cut performs amazingly and also displays a controlled play of light based on its design. The problem is the AGS 1 grade can't be translated into a top cut simply because it's grade is based on that "bad" leakage where the pics and asset clearly show it's not.

Maybe if we could have the algorithm numerical value listed on the grading reports we could have a better chance utilizing the AGSL grading system for other cuts rather than just triple 0's.

I think consumers will be better informed if we can show them how the grade was set.

 

[teobdl]

DiaGem--
Setting that diamond to take full advantage of the light entering below the girdle would be very important information for the owner of that kind of diamond, or any other that was designed in this way.

Prongs would block, maybe, 30% of light entering just below the girdle?

When set, would those areas in the corner of the table not be darker than what's in those pictures?

 

[Karl_K]

There is a big boogie man in the diamond industry holding back diamond design is fear of numbers outside the norm for that cut. I run into it with Octavia and Paul ran into it with his princess cuts.
It infects both trade and consumers. That is one reason cut research is so important.
Replace numbers with performance metrics.
Unfortunately there isn't one yet that works all that well that covers all aspects of diamond light behavior.
If anything AGSL cut grading hurts research in the designs they have grades that became popular for the same reasons.
Between ags0 and gia ex there is 0 reason to even work with RBs because if it don't meet one or both of them it is practically unsalable.

 

[Texas Leaguer]

Bryan - the reason why Garry's comment that projected his own preferences onto "most" consumers surprised me was precisely because that statement seemed inconsistent to me with the extremely measured and objective approach in the terrific Rappaport article I read yesterday on my way home from work.

It is no secret that Garry doesn't like what he considers "crushed ice" in colorless diamonds. But the larger flashes characteristic of round brilliants are not better or worse than the smaller flashes characteristic of well cut radiants. They are simply different as are the broader flashes of a well cut step cut. Some folks will prefer one style, others another and while science can explain why each style appears as it does and can help consumers understand what they are seeing, it can't "rank" them in some kind of gemological order.

I have often encountered consumers who start the conversation saying "I don't want "crushed ice" who then fall in love with a well cut radiant because the diamonds look very different than the discussions about "crushed ice" led them to believe they would look like.

Obviously we all have personal preferences and all I am suggesting is that it's important to at least try to separate those preferences from our scientific analysis. I like the way my original radiants reflect light far better than the way princesses reflect light. So, in my experience, do many people. Perhaps most. In my experience it is most when they make the comparison side by side.

Obviously my preference (and my belief that most people share it) involves more than a little self interest, but I have never said (and would never say) that radiants are gemologically superior to princesses. I tell folks that the two styles reflect light differently, they're supposed to, and they should look at both and choose the one that they like best.

This doesn't mean that I think beauty is completely subjective and there's no such thing as "better" and "worse" cuts within the same style. Of course I do. After all, I am very much in the fine cut businesses and that means I believe there is a very real and substantial difference between my Original Radiants and most generics that is readily apparent when the diamonds are viewed side by side (I hope I didn't break any rules there!).

At the end of the day we're not really disagreeing about much here - just about whether we should choose our language a little more carefully so consumers are clear about when we are describing science, and when we are describing our personal tastes. And I would welcome the opportunity to work with Garry and the cut group since I think the work that they've done is absolutely amazing - by far the most serious effort I know of to truly understand diamond optics.

Stan, I hear you. It is important to respect different opinions on what is beautiful/valuable in a given diamond. I think the key is continuing to break down the individual aspects of diamond light performance, combined with what we are leaning about nueroscience and match that up to results of the diagnostic tools that are in use, particularly as regards those tools being used to assist remote buying. It will eventually be possible to look at information such as an ASET signature of a certain facet arrangement and be able to predict more accurately what we should expect to see in terms of overall aesthetics and where the tradeoffs might be for such things as fire and spread.

Our trade is primarily in precision cut rounds and princess which are somewhat better understood. But if my trade was in fancies, I'm sure I would be devoting myself to understanding (and attempting to demonstrate) which ASET signatures are associated with diamonds of top eye appeal, and why some conventional concepts about ASET signatures might be misleading. I think that to the extent one can do that, you not only perform a valuable service to the market, but you give yourself a real competitive advantage as a seller.

 

[Rockdiamond]

DiaGem--
Setting that diamond to take full advantage of the light entering below the girdle would be very important information for the owner of that kind of diamond, or any other that was designed in this way.

Prongs would block, maybe, 30% of light entering just below the girdle?

When set, would those areas in the corner of the table not be darker than what's in those pictures?

this s a great question!
In my experience, many diamond designs are affected by light entering the pavilion- particularly in the setting.
I have not noticed it specifically affect the prong areas as you suggested- however I have never set a diamond like the new one Yoram posted. (yet )

 

[MelisendeDiamonds]

Bryan- its the mixing of subjective and objective that I feel is pejorative towards certain types of cuts. And I am by no means the only one who feels this way. If you read the posts, Stan agrees with me. My "long campaign" is due to the fact that it's been this way since at least 2006.

AGSL has been referred to here- and they have an agenda in promoting what they term "Light Performance"- which has absolutely ZERO to do with beauty, or even how well a given diamond is cut.

One of the marketing claims made by the Original Radiant Cut brand (ORC) a "Crushed Ice Design" that you are constantly promoting here is as follows:

Unmatched Brilliance. Our strict adherence to Mr. Grossbard's cut standards, means every one of our diamonds possesses unparalleled brilliance.
http://radiantcut.com/OriginalGeneric.aspx

That seems like a rather lofty and unsupported claim especially considering the spread requirements of the brand.

I for one am very interested to see how you and Radiantman(Stan Grossbard) are going to explain with proof how the Rectangular ORCs have "Unmatched Brilliance" once you finally show us the ASET images or provide scans.

Seems that isn't going to happen and that perhaps your combined agendas as sellers of the ORC brand aren't being served well by ASET or this thread and you have taken great efforts to discredit and point out complexities to its interpretation.

The Crushed Ice that you seem to promote so much (ORC for example) is gaining spread and cheaper price at the expense of brilliance and fire. https://www.pricescope.com/communit...ancy-cuts.204414/page-3#post-3723957#p3723957 Top One.

Alternatively the "Light Performance" or "AGS 0" diamonds that are often favoured here cost more per carat and may have smaller spread.
https://www.pricescope.com/communit...ancy-cuts.204414/page-3#post-3723957#p3723957 Bottom One.

We don't sell niche Fancy shapes at the moment, no ORC, or any AGS 0 Fancy shapes, currently our resources are focussed on the largest segment of the market which doesn't include a lot of cut cornered squares. If I did venture into this area I'd definitely use side by side comparisons and maybe order a Vibox or Dibox from Garry one day. We would be confident in presenting the tradeoffs and informing our customers of the weaknesses of one brand over another. I think transparency and full disclosure helps in sales and you never lose much by explaining the weaknesses in what you sell. You can be sure your competitors are already trying to do that.

 

[diagem]

At the end of the day we're not really disagreeing about much here - just about whether we should choose our language a little more carefully so consumers are clear about when we are describing science, and when we are describing our personal tastes. And I would welcome the opportunity to work with Garry and the cut group since I think the work that they've done is absolutely amazing - by far the most serious effort I know of to truly understand diamond optics.

I fully agree with Radiantman's writing here.
It would be best for all interests if we differentiate a bit more in our wordings on the subjects of science and personal "beauty" tastes. I fully understand where RD & Radiantman are coming from.
I too am grateful for the Diamond optics education well received by the extended cut group, I say extended because even though the "cut group" might be the pioneers I was lucky to absorb a lot of that cool-aid from a plurality of knowledgeable friends including consumers.

I also fully agree with the science and am continually researching to better understand it every day. The potential in light designed Diamonds is enormous but realistically we are still in our diaper stage..., in the mean time I have been cutting and designing Diamonds, some are amazing and based on the science of light not to mention their cutting complexities and some are just beautiful which are based on our good old 300 year of primitive science..., ok, with some modern technological help Our clients feedback from both opposite poles are equally positive.

We must advocate more freedom of expression. Beautiful Diamonds are unmeasurable!
I understand the issues in stake with the "trust my eyes" marketing dangers to consumers but also know and feel this industry is becoming more transparent by the day, transparency translates to education, industry members already know they must change their "old habits" if they wish to survive in this industry. The only way is by education and I feel more are learning.
Our transformation into a wide range added value industry is inevitable, Diamonds and the way they are being marketed is changing extremely fast. You really need to notice the recent changes happening in the rough distribution models & channels to perhaps better understand where marketing can potentially be heading towards.

If we utilize science as a consumer protector we limit our freedom of moving forward.

 

[diagem]

DiaGem--
Setting that diamond to take full advantage of the light entering below the girdle would be very important information for the owner of that kind of diamond, or any other that was designed in this way.

Prongs would block, maybe, 30% of light entering just below the girdle?

When set, would those areas in the corner of the table not be darker than what's in those pictures?

this s a great question!
In my experience, many diamond designs are affected by light entering the pavilion- particularly in the setting.
I have not noticed it specifically affect the prong areas as you suggested- however I have never set a diamond like the new one Yoram posted. (yet )

That's exactly the point of light designed Diamonds, their purpose is to emphasize a specific appearance, in this case a solid red (Aset) center star. Sure, it "might" have an effect but who says its negative? Don't all settings have the potential to affect? Let's not forget it's still a respectable AGSL 1 for LP (0.91 deduction vs a 0.49 needed for a 0 grade) and will probably earn 0's for both symmetry and polish.
Based on our tests, it's not that sensitive as you might imagine.

 

[diagem]

Bryan- its the mixing of subjective and objective that I feel is pejorative towards certain types of cuts. And I am by no means the only one who feels this way. If you read the posts, Stan agrees with me. My "long campaign" is due to the fact that it's been this way since at least 2006.

AGSL has been referred to here- and they have an agenda in promoting what they term "Light Performance"- which has absolutely ZERO to do with beauty, or even how well a given diamond is cut.

One of the marketing claims made by the Original Radiant Cut brand (ORC) a "Crushed Ice Design" that you are constantly promoting here is as follows:

Unmatched Brilliance. Our strict adherence to Mr. Grossbard's cut standards, means every one of our diamonds possesses unparalleled brilliance.
http://radiantcut.com/OriginalGeneric.aspx

That seems like a rather lofty and unsupported claim especially considering the spread requirements of the brand.

I for one am very interested to see how you and Radiantman(Stan Grossbard) are going to explain with proof how the Rectangular ORCs have "Unmatched Brilliance" once you finally show us the ASET images or provide scans.

Seems that isn't going to happen and that perhaps your combined agendas as sellers of the ORC brand aren't being served well by ASET or this thread and you have taken great efforts to discredit and point out complexities to its interpretation.



The Crushed Ice that you seem to promote so much (ORC for example) is gaining spread and cheaper price at the expense of brilliance and fire. https://www.pricescope.com/communit...ancy-cuts.204414/page-3#post-3723957#p3723957 Top One.

Alternatively the "Light Performance" or "AGS 0" diamonds that are often favoured here cost more per carat and may have smaller spread.
https://www.pricescope.com/communit...ancy-cuts.204414/page-3#post-3723957#p3723957 Bottom One.

We don't sell niche Fancy shapes at the moment, no ORC, or any AGS 0 Fancy shapes, currently our resources are focussed on the largest segment of the market which doesn't include a lot of cut cornered squares. If I did venture into this area I'd definitely use side by side comparisons and maybe order a Vibox or Dibox from Garry one day. We would be confident in presenting the tradeoffs and informing our customers of the weaknesses of one brand over another. I think transparency and full disclosure helps in sales and you never lose much by explaining the weaknesses in what you sell. You can be sure your competitors are already trying to do that.

Sorry MD, I don't believe in these methods. Attacking will not help us move forward on such long and often heated discussions. It didn't seem to help for years and I don't believe you are going to break that subject now.
Discussing it professionally on the other hand might develop fruits.
We are after all professionals here..., let's keep that respect level please!

 

[MelisendeDiamonds]

DiaGem--
Setting that diamond to take full advantage of the light entering below the girdle would be very important information for the owner of that kind of diamond, or any other that was designed in this way.

Prongs would block, maybe, 30% of light entering just below the girdle?

When set, would those areas in the corner of the table not be darker than what's in those pictures?

this s a great question!
In my experience, many diamond designs are affected by light entering the pavilion- particularly in the setting.
I have not noticed it specifically affect the prong areas as you suggested- however I have never set a diamond like the new one Yoram posted. (yet )

That's exactly the point of light designed Diamonds, their purpose is to emphasize a specific appearance, in this case a solid red (Aset) center star. Sure, it "might" have an effect but who says its negative? Don't all settings have the potential to affect? Let's not forget it's still a respectable AGSL 1 for LP (0.91 deduction vs a 0.49 needed for a 0 grade) and will probably earn 0's for both symmetry and polish.
Based on our tests, it's not that sensitive as you might imagine.

How much of that deduction is Brightness deduction versus Leakage?

 

[MelisendeDiamonds]

Sorry MD, I don't believe in these methods. Attacking will not help us move forward on such long and often heated discussions. It didn't seem to help for years and I don't believe you are going to break that subject now.
Discussing it professionally on the other hand might develop fruits.
We are after all professionals here..., let's keep that respect level please!

You've done much the same thing, the "AGSL must be too "rigid" if it won't give my "All red star" its top cut grade".
The reason why that design doesn't receive/deserve it is there wouldn't be as much life in the corners of the table in most lighting and especially in most settings where the girdle is protected(covered).

These look familiar to you?



Beautiful bright diamond, but not without room for improvement.

I for one am glad AGSL has rigid standards, they could easily sell out and try to accommodate everyone who submits a design, they would surely get more business that way at the expense of diluting their reputation and the quality of their brand.

 

[Garry H (Cut Nut)]

There is a big boogie man in the diamond industry holding back diamond design is fear of numbers outside the norm for that cut. I run into it with Octavia and Paul ran into it with his princess cuts.
It infects both trade and consumers. That is one reason cut research is so important.
Replace numbers with performance metrics.
Unfortunately there isn't one yet that works all that well that covers all aspects of diamond light behavior.
If anything AGSL cut grading hurts research in the designs they have grades that became popular for the same reasons.
Between ags0 and gia ex there is 0 reason to even work with RBs because if it don't meet one or both of them it is practically unsalable.

There are a couple of threads here.
Karl and DiaGem following on - I would like to address the basis of existing cut grade systems - they all fail because they are not open ended and they use different scoring systems for different shapes. That is wrong (as Sergey has been saying for more than a decade).
By scoring everything against Tolkowsky (DC1.00), it is possible to achieve better in some aspects (e.g. Fire 1.05) and worse in others (say brilliance or scintillation 0.95). This can give consumers the chance to find diamonds that meet their preferences. A waitress or restauranteur may prefer a firey diamond for example.

 

[Garry H (Cut Nut)]

Bryan - the reason why Garry's comment that projected his own preferences onto "most" consumers surprised me was precisely because that statement seemed inconsistent to me with the extremely measured and objective approach in the terrific Rappaport article I read yesterday on my way home from work.

It is no secret that Garry doesn't like what he considers "crushed ice" in colorless diamonds. But the larger flashes characteristic of round brilliants are not better or worse than the smaller flashes characteristic of well cut radiants. They are simply different as are the broader flashes of a well cut step cut. Some folks will prefer one style, others another and while science can explain why each style appears as it does and can help consumers understand what they are seeing, it can't "rank" them in some kind of gemological order.

I have often encountered consumers who start the conversation saying "I don't want "crushed ice" who then fall in love with a well cut radiant because the diamonds look very different than the discussions about "crushed ice" led them to believe they would look like.

Obviously we all have personal preferences and all I am suggesting is that it's important to at least try to separate those preferences from our scientific analysis. I like the way my original radiants reflect light far better than the way princesses reflect light. So, in my experience, do many people. Perhaps most. In my experience it is most when they make the comparison side by side.

Obviously my preference (and my belief that most people share it) involves more than a little self interest, but I have never said (and would never say) that radiants are gemologically superior to princesses. I tell folks that the two styles reflect light differently, they're supposed to, and they should look at both and choose the one that they like best.

This doesn't mean that I think beauty is completely subjective and there's no such thing as "better" and "worse" cuts within the same style. Of course I do. After all, I am very much in the fine cut businesses and that means I believe there is a very real and substantial difference between my Original Radiants and most generics that is readily apparent when the diamonds are viewed side by side (I hope I didn't break any rules there!).

At the end of the day we're not really disagreeing about much here - just about whether we should choose our language a little more carefully so consumers are clear about when we are describing science, and when we are describing our personal tastes. And I would welcome the opportunity to work with Garry and the cut group since I think the work that they've done is absolutely amazing - by far the most serious effort I know of to truly understand diamond optics.

Stan the most accurate and best comment on this page 7 of our rambles is that your's and mine (and everyone else's) opinions about a particular diamond are "meaningless". The only opinion that counts is that of the person that buys it. No argument here.

But we still need to be able to find out what people like and then make diamonds that have more of those features. Its a worthy goal.

 

[diagem]

Sorry MD, I don't believe in these methods. Attacking will not help us move forward on such long and often heated discussions. It didn't seem to help for years and I don't believe you are going to break that subject now.
Discussing it professionally on the other hand might develop fruits.
We are after all professionals here..., let's keep that respect level please!

You've done much the same thing, the "AGSL must be too "rigid" if it won't give my "All red star" its top cut grade".
The reason why that design doesn't receive/deserve it is there wouldn't be as much life in the corners of the table in most lighting and especially in most settings where the girdle is protected(covered).

These look familiar to you?



Beautiful bright diamond, but not without room for improvement.

I for one am glad AGSL has rigid standards, they could easily sell out and try to accommodate everyone who submits a design, they would surely get more business that way at the expense of diluting their reputation and the quality of their brand.

On the contrary MD, and please don't put words in my mouth..., it's becoming annoying!
The image you just posted above is of an early edition to this latest one (which I posted) which was far from the 3D cut precision it presently entails.
The problem isn't if this design gets the 0 or not (it never was), on the contrary, this cut can be easily be amended into a solid 0 by a slight changing of a few proportions as AGSL suggested to me while analyzing the file but that was not my objective nor my objective in participating in this thread!
Pity, you seemed to me like an interesting, knowledgeable person to enter into a professional discussion. You surely managed to reveal a different agenda which I won't participate in.

 

[RADIANTMAN]

[quote="
Stan the most accurate and best comment on this page 7 of our rambles is that your's and mine (and everyone else's) opinions about a particular diamond are "meaningless". The only opinion that counts is that of the person that buys it. No argument here.

But we still need to be able to find out what people like and then make diamonds that have more of those features. Its a worthy goal.[/quote]


Garry we mostly agree. One of the most important contributions my Dad made to the industry with the introduction of the Radiant was to show people it was OK to expand the menu of choices available to consumers. By doing that, the Radiant really paved the way for the era of innovation we are experiencing now.

Where we may disagree is over whether the new choices will objectively "better" because they are designed using a more sophisticated understanding of optics than existed "back in the day." In my opinion whether a cut is "better" or "worse" will remain just as subjective as it always was. Particular characteristics can be objectively measured but measuring characteristics does not yield a measurement of beauty.

Some people will choose the new cuts while others will prefer existing cuts. People should make their choices based on their own tastes and based on what particular characteristics are important to them either visually or intellectually.

To be important contributions to our industry it's not necessary that most people prefer the new cuts, only that enough people do, and I think we need to be careful not to create a uniform evaluation standard that limits rather than expands the scope of innovation.

 

[Serg]

[quote="
Stan the most accurate and best comment on this page 7 of our rambles is that your's and mine (and everyone else's) opinions about a particular diamond are "meaningless". The only opinion that counts is that of the person that buys it. No argument here.

But we still need to be able to find out what people like and then make diamonds that have more of those features. Its a worthy goal.

Garry we mostly agree. One of the most important contributions my Dad made to the industry with the introduction of the Radiant was to show people it was OK to expand the menu of choices available to consumers. By doing that, the Radiant really paved the way for the era of innovation we are experiencing now.

Where we may disagree is over whether the new choices will objectively "better" because they are designed using a more sophisticated understanding of optics than existed "back in the day." In my opinion whether a cut is "better" or "worse" will remain just as subjective as it always was. Particular characteristics can be objectively measured but measuring characteristics does not yield a measurement of beauty.

Some people will choose the new cuts while others will prefer existing cuts. People should make their choices based on their own tastes and based on what particular characteristics are important to them either visually or intellectually.

To be important contributions to our industry it's not necessary that most people prefer the new cuts, only that enough people do, and I think we need to be careful not to create a uniform evaluation standard that limits rather than expands the scope of innovation.[/quote]

Vines are different , Vine taste is very subjective. But some vines are definitely much better than others for most vine consumers.
Also new technologies help create better vines with better consistency . See for example modern Switzerland vines history.
last10-20 years Swiss vine makers invest a lot money and efforts in new vine technologies. result is amazing.

 

[MelisendeDiamonds]

Pity, you seemed to me like an interesting, knowledgeable person to enter into a professional discussion. You surely managed to reveal a different agenda which I won't participate in.

Garry, the actual Diamond in the picture you posted is on a black background.
We notice that "ring" area is not actually all leakage, I even think most of that area is lit up by light entering just below 45 degrees, an area AGSL doesnt take into consideration when grading for LP (thats without taking tilt into consideration on this specific example you posted).

Thanks Diagem I think I'll explain myself more clearly so you aren't left guessing an "Agenda".

My disagreement with Radiantman and Rockdiamond is that the my own investigation shows that the ORC I studied is less brilliant than some other designs and the ASET isn't misleading anyone when it highlights that difference. As John Pollard said More Brilliant is More.
Less is Less. I think that marketing statement I posted in large above does not allow this fact to be recognized.

I didn't say one is more beautiful than the other but it is certainly less brilliant. If that wasn't the case there would be no justification for tradeoff in spread and yield and those "AGS 0" designs would not be sellable. I think you can appreciate the additional costs involved in cutting to AGS 0 standards and I am sure Texas Leaguer does as well.

-------------------------------------------------------------------------------------------------------------------------------------------------------------

Then our discussion on ASET grey, I don't see a big difference between grey (partial leakage) and white.
The corners of the table in those pictures and the video I saw a while ago look dull and lifeless and sure they may flash more often than -90 degree leakage areas under certain tilt or lighting but for the most part they are not high life areas.



I would expect a similar signature from the diamond you posted with this ASET.


Here is another example:



Complicating trying to interpret where the grey regions or partial leakage is not something that I believe will be helpful to understanding or applying the tool. That will confuse most people as there is no key for what Grey means or what mixed colors mean. Also you won't be able to easily resolve the grey in non backlit ASET.

The ASET is only designed to look at a half hemisphere above the girdle and purposefully so, most of the life of a diamond comes from lighting in that upper hemisphere.

Finally if AGSL cut grading (AGS-PGS not an ASET 30 image) were so inclined to consider some reduction in the leakage score to account for "low angle leakage" the grey arrows below.



If the Brightness deduction is already above 0.49 due to those regions it isn't going to make much a difference it would still not be an AGS 0.

This doesn't detract from the beauty of the design but it does indicate less brilliance and may well change how it is marketed and whether you send it to AGSL.

 

[Serg]

Pity, you seemed to me like an interesting, knowledgeable person to enter into a professional discussion. You surely managed to reveal a different agenda which I won't participate in.

Garry, the actual Diamond in the picture you posted is on a black background.
We notice that "ring" area is not actually all leakage, I even think most of that area is lit up by light entering just below 45 degrees, an area AGSL doesnt take into consideration when grading for LP (thats without taking tilt into consideration on this specific example you posted).

Thanks Diagem I think I'll explain myself more clearly so you aren't left guessing an "Agenda".

My disagreement with Radiantman and Rockdiamond is that the my own investigation shows that the ORC I studied is less brilliant than some other designs and the ASET isn't misleading anyone when it highlights that difference. As John Pollard said More Brilliant is More.
Less is Less. I think that marketing statement I posted in large above does not allow this fact to be recognized.

I didn't say one is more beautiful than the other but it is certainly less brilliant. If that wasn't the case there would be no justification for tradeoff in spread and yield and those "AGS 0" designs would not be sellable. I think you can appreciate the additional costs involved in cutting to AGS 0 standards and I am sure Texas Leaguer does as well.

-------------------------------------------------------------------------------------------------------------------------------------------------------------

Then our discussion on ASET grey, I don't see a big difference between grey (partial leakage) and white.
The corners of the table in those pictures and the video I saw a while ago look dull and lifeless and sure they may flash more often than -90 degree leakage areas under certain tilt or lighting but for the most part they are not high life areas.



I would expect a similar signature from the diamond you posted with this ASET.


Here is another example:



Complicating trying to interpret where the grey regions or partial leakage is not something that I believe will be helpful to understanding or applying the tool. That will confuse most people as there is no key for what Grey means or what mixed colors mean. Also you won't be able to easily resolve the grey in non backlit ASET.

The ASET is only designed to look at a half hemisphere above the girdle and purposefully so, most of the life of a diamond comes from lighting in that upper hemisphere.

Finally if AGSL cut grading (AGS-PGS not an ASET 30 image) were so inclined to consider some reduction in the leakage score to account for "low angle leakage" the grey arrows below.



If the Brightness deduction is already above 0.49 due to those regions it isn't going to make much a difference it would still not be an AGS 0.

This doesn't detract from the beauty of the design but it does indicate less brilliance and may well change how it is marketed and whether you send it to AGSL.

There is big difference between grey (partial leakage) and white ASET zones.

http://www.gemology.ru/cut/english/conferens-article/6.htm
"b) Subjective brightness depends on luminance; a small amount of leakage will have a much smaller effect on subjective brightness because the relationship between perceived brightness and light return is not linear. For example direct light measurement devices that implement various lighting schemes may reveal partial light leakage through a diamonds pavilion facets. Observation of a leakage area might lead the observer to conclude that this area of the diamond will not appear to sparkle, where-as the partial light return area may still be perceived as sparkling. In an example from fig. 3, one particular area in this diamond may have 50% leakage, but the same area has 85% of subjective light return into an eye."

 

[Rockdiamond]

Great point Serg!!
In other words, that's why an area that may show as white or grey in ASET flashes bright in real life. Yes?

 

[Rockdiamond]

MD- no matter one's opinion, keeping the discussion free of malice is the only way to truly exchange ideas.
No one is promoting anything on this thread- except maybe new, and or different ideas.

Every trades-person here has a lot at stake. And every trades-person contributing in this thread brings valuable perspective.
In return, PriceScope graciously allows our signature. If anyone is violating policies, my experience is that PS mgmt will take appropriate action.
If someone is here promoting something, by all means, report it.
Let's keep the discussion on a positive note for everyone's benefit.
We can have different viewpoints respectfully.

 

[Serg]

Great point Serg!!
In other words, that's why an area that may show as white or grey in ASET flashes bright in real life. Yes?

David,
In previous post I did not say that white ASET zones may give bright flashes.
I explained why partial leakage ( grey Zone in ASET, IS) does not equal to low light return .
but white ASET Zone may give " bright flashes in real life". ( reason is different)

In same time all these my explanations do not support your statements about crushed Ice diamond .
In light environment with black down hemisphere all known me Crushed Ice cuts have significantly less brightness than RBC.

it would be possible to design Crushed type cut( many number of internal light reflections ) without significant leakage but it is not possible yet to produce it with necessary accuracy .
meanwhile better to use cuts with low number internal light reflections to create pattern with small VF's( it is possible) ( Less chaos may give better brightness with same scintillation )

 

[Rockdiamond]

HI Serg,
We agree that in terms of raw brilliance, larger reflections that bounce less before exiting the diamond are brightest. Not best, but brightest.
I know exactly what you mean when you say "less chaotic"
But sometimes you get a more even sparkle- if somewhat less brilliant, by making sure all the VF's are small.
Basically, when he VF's are larger, we increase brightness, but also contrast that sometimes look like dark areas in a sea of sparkle.

By the way- I want to be clear that I learn a lot fro these discussions. I respect the work you and Garry do. I completely respect that you are in the business of figuring out how to make diamonds look best in your view.
Since I deal with the finished product, and I don't want to learn to cut, or design diamonds I have a pragmatic viewpoint.

I want to be as good a buyer of polished diamonds as I can be.
When I'm buying, I can't take a lot of time to figure out exactly why a diamond looks great. If it's being offered to me, and I love it, I generally buy it.
Since there's so much variation of shape and facet design, it's generally not practical to expect consistency in market, non branded goods. In other words, if I find a marquise ( for example) that I really love, I'm not notating what to look for in the next one.
I deal with the stones as they come.

When they look bad ( which is often) I don't have the time to try to figure out why.

I leave that to you guys

 

[Karl_K]

David,
Discussing VF size without considering lighting is like discussing how fast a car is without considering how much power it has under the hood.
Take a diamond with tons of small VF and one with fewer larger VFs both are efficient at retuning light to the eye and change the lighting and the rankings can and will change.
In bright direct lighting the diamond with tons of small VFs will have an edge, put the same diamonds in dim indirect lighting and the situation will change with the diamond with larger VFs having an edge.
My answer was med sized VFs that are large enough to be effective in low light and a lot of them.
A modern ideal cut RBs answer is everything including the kitchen sink for VF size in one diamond.