IGI, GiA, AGL-gem labs

[V_sh]

That ideal-scope image is not of the proportions listed

For sure it shocked you Garry

I was also shocked two years ago when I was studying this cut

I designed based on these proportions and got the same result, just give it a try and redesign it, and you will see the same ideal-scope pattern (Brillianteering is negligible for this cut)

After that if you aren't convinced I'll send you more details about it, or maybe its .gem file

GIA, AGS, HRD, GCAL, Sarin, IGI, and WTOCD can not grade such a diamond as a "good" light performance one due to their lack of information; their charts are based on mathematically wrong information as old as my ancestors (back to 1919)

It's time to change and almost no one in the industry is willing to.

@Garry H (Cut Nut) I would appreciate it if you tell us how you grade a diamond with these proportions, how does HCA grade this?

@smitcompton Do you like to buy a diamond with these proportions?

@Rockdiamond Could you please share your valuable opinion about this diamond cut? do you accept it as a good cut?

@Texas Leaguer Could you please tell us your valuable opinion, is this stone a possible competitor for ACA? How would "Sarin" grade such a stone?

@Karl_K Could you please redesign this cut and inform us about your opinion and the grade of this cut based on IGI's new grading experiments? also if you share the grades that "Gem Adviser" suggests for this cut I'd appreciate it.

@0-0-0 Could you please let us know your opinion about this cut based on your experiments? Do you grade it as a superior cut?

@Serg Could you please regrade this diamond with your new grading system for us and share the result? And if possible a comparison with an accurate H&A like ACA, Please


Your valuable answers will help the whole market, I'll appreciate it


Real images related to the discussed stone

Main Pavilion: 39.98°
Lower girdle: 41.05°
Lower girdle length: 80.5%

Main crown: 39.05°
Star: 25.81°
Star length: 61.7%
Table: 60.95%
Upper girdle: 49°

Brillianteering: Negligible

 

[smitcompton]

Hi,
I learned a lot from this discussion. Kenny hit one aspect right on by saying that there are different markets for different people. Some want the best , other want very good.

Since I haven't seen my diamond in person yet, I cannot be sure if I will like it in real life. If it sparkles beautifully and shows no inclusion, Ill be only concerned about the K color. If this does not meet my expectation I shall send it back to James.

I did chuckle a bit when I read that LightBox(DeBeers) is sending some of their stones to GIA. I guess so that they too can charge more. How funny.

0-0-0-- very nice explanation--thanks

015- Thank you again.

Annette

 

[Karl_K]

@V_sh im not at my computer but have researched similar cuts.
They are called 40/40 cuts. Near 40ca and 40pa.
There is a small pocket of nicely performing combinations in that area.
Spread however was not great.

It is not possible nor practical to include all such pockets in any grading system. They are not practical.

 

[Serg]

For sure it shocked you Garry

I was also shocked two years ago when I was studying this cut

I designed based on these proportions and got the same result, just give it a try and redesign it, and you will see the same ideal-scope pattern (Brillianteering is negligible for this cut)

After that if you aren't convinced I'll send you more details about it, or maybe its .gem file

GIA, AGS, HRD, GCAL, Sarin, IGI, and WTOCD can not grade such a diamond as a "good" light performance one due to their lack of information; their charts are based on mathematically wrong information as old as my ancestors (back to 1919)

It's time to change and almost no one in the industry is willing to.

@Garry H (Cut Nut) I would appreciate it if you tell us how you grade a diamond with these proportions, how does HCA grade this?

@smitcompton Do you like to buy a diamond with these proportions?

@Rockdiamond Could you please share your valuable opinion about this diamond cut? do you accept it as a good cut?

@Texas Leaguer Could you please tell us your valuable opinion, is this stone a possible competitor for ACA? How would "Sarin" grade such a stone?

@Karl_K Could you please redesign this cut and inform us about your opinion and the grade of this cut based on IGI's new grading experiments? also if you share the grades that "Gem Adviser" suggests for this cut I'd appreciate it.

@0-0-0 Could you please let us know your opinion about this cut based on your experiments? Do you grade it as a superior cut?

@Serg Could you please regrade this diamond with your new grading system for us and share the result? And if possible a comparison with an accurate H&A like ACA, Please


Your valuable answers will help the whole market, I'll appreciate it


Real images related to the discussed stone

Main Pavilion: 39.98°
Lower girdle: 41.05°
Lower girdle length: 80.5%

Main crown: 39.05°
Star: 25.81°
Star length: 61.7%
Table: 60.95%
Upper girdle: 49°

Brillianteering: Negligible

You could find several diamonds like this on Cutwise

https://cutwise.com/compare/diamond-colorless?id[]=135906&id[]=17149&id[]=385

MSS15, MSS17 had been designed and cut by us( Cut group ) 10-15 years ago

Master Stone Set

List of all MSS diamonds PGS report Cutting Rules AGS & GIAAGS GOLD 2008 & AGSPGS Chart for Table 57%GIA, AGS GOLD 2008 & AGSPGS ChartsGIA & AGSPGS Put mouse over the diamond in t…

www.octonus.com

it is very long story

 

[V_sh]

@V_sh im not at my computer but have researched similar cuts.
They are called 40/40 cuts. Near 40ca and 40pa.
There is a small pocket of nicely performing combinations in that area.
Spread however was not great.

It is not possible nor practical to include all such pockets in any grading system. They are not practical.

Thanks a lot Karl,

I do agree with you about the "small pocket" and the spread but does not mean this kind of cut is not worth considering.

About the spread, this cut can be efficient for some rough shapes, but manufacturers don't consider it very well as labs don't grade it as a good one.

Thanks for sharing the information and participating

You could find several diamonds like this on Cutwise

https://cutwise.com/compare/diamond-colorless?id[]=135906&id[]=17149&id[]=385

MSS15, MSS17 had been designed and cut by us( Cut group ) 10-15 years ago

Master Stone Set

List of all MSS diamonds PGS report Cutting Rules AGS & GIAAGS GOLD 2008 & AGSPGS Chart for Table 57%GIA, AGS GOLD 2008 & AGSPGS ChartsGIA & AGSPGS Put mouse over the diamond in t…

www.octonus.com

it is very long story

Thank you so much Sergey,

Yeah I saw some of them, good scores they get.

MSS project proof a lot of problems in grading systems, but seems no one cares.

MSS17 fascinates me:

OctoNus : Master Stone Set - diamond 17

And worthy stories are mostly long ones

thanks for participating

 

[Serg]

re: MSS project proof a lot of problems in grading systems, but seems no one cares.



The diamond industry is conservative not by accident and not out of malice. This conservatism is a result of a business model chosen many decades ago, based on the selected niche (engagement) and marketing slogans like "Diamond Forever" and "Ideal Cut."

For over 100 years, the round cut has been the most conservative part of this already conservative market, even though it was actively evolving 2-3 centuries ago. However, after the modern round cut was created about 100 years ago through trial and error and extensive active evolution, its further development lost practical value. Now, it is primarily a symbol rather than a product of technological advancement. The value of a symbol decreases if it changes, so it is not beneficial for the market (and not just for laboratories or sellers) to change this symbol. No matter who finds better proportions, it will not enhance the commercial value of the symbol.

Those who seek innovation in cuts and cut evaluation technologies should not waste their time on the classic round cut. Fancy cuts offer significantly more opportunities for development, self-expression, and the creation of new brands.



In the diamond industry, the product remained virtually unchanged for a long time, so sales were maintained through constant changes in advertising, slogans like "Ideal," "Triple Excellent," "True Ideal," and so on.

However, it should be the exact opposite. The advertising message describing the brand's value should be conservative and rarely change, while the product itself should continuously evolve and improve.

 

[Garry H (Cut Nut)]

For sure it did not. I knew this 25 years ago when I developed HCA

For sure it shocked you Garry

I was also shocked two years ago when I was studying this cut

I designed based on these proportions and got the same result, just give it a try and redesign it, and you will see the same ideal-scope pattern (Brillianteering is negligible for this cut)

After that if you aren't convinced I'll send you more details about it, or maybe its .gem file

GIA, AGS, HRD, GCAL, Sarin, IGI, and WTOCD can not grade such a diamond as a "good" light performance one due to their lack of information; their charts are based on mathematically wrong information as old as my ancestors (back to 1919)

It's time to change and almost no one in the industry is willing to.

@Garry H (Cut Nut) I would appreciate it if you tell us how you grade a diamond with these proportions, how does HCA grade this?

@smitcompton Do you like to buy a diamond with these proportions?

@Rockdiamond Could you please share your valuable opinion about this diamond cut? do you accept it as a good cut?

@Texas Leaguer Could you please tell us your valuable opinion, is this stone a possible competitor for ACA? How would "Sarin" grade such a stone?

@Karl_K Could you please redesign this cut and inform us about your opinion and the grade of this cut based on IGI's new grading experiments? also if you share the grades that "Gem Adviser" suggests for this cut I'd appreciate it.

@0-0-0 Could you please let us know your opinion about this cut based on your experiments? Do you grade it as a superior cut?

@Serg Could you please regrade this diamond with your new grading system for us and share the result? And if possible a comparison with an accurate H&A like ACA, Please


Your valuable answers will help the whole market, I'll appreciate it


Real images related to the discussed stone

Main Pavilion: 39.98°
Lower girdle: 41.05°
Lower girdle length: 80.5%

Main crown: 39.05°
Star: 25.81°
Star length: 61.7%
Table: 60.95%
Upper girdle: 49°

Brillianteering: Negligible

 

[V_sh]

re: MSS project proof a lot of problems in grading systems, but seems no one cares.



The diamond industry is conservative not by accident and not out of malice. This conservatism is a result of a business model chosen many decades ago, based on the selected niche (engagement) and marketing slogans like "Diamond Forever" and "Ideal Cut."

For over 100 years, the round cut has been the most conservative part of this already conservative market, even though it was actively evolving 2-3 centuries ago. However, after the modern round cut was created about 100 years ago through trial and error and extensive active evolution, its further development lost practical value. Now, it is primarily a symbol rather than a product of technological advancement. The value of a symbol decreases if it changes, so it is not beneficial for the market (and not just for laboratories or sellers) to change this symbol. No matter who finds better proportions, it will not enhance the commercial value of the symbol.

Those who seek innovation in cuts and cut evaluation technologies should not waste their time on the classic round cut. Fancy cuts offer significantly more opportunities for development, self-expression, and the creation of new brands.



In the diamond industry, the product remained virtually unchanged for a long time, so sales were maintained through constant changes in advertising, slogans like "Ideal," "Triple Excellent," "True Ideal," and so on.

However, it should be the exact opposite. The advertising message describing the brand's value should be conservative and rarely change, while the product itself should continuously evolve and improve.

It seems to me that these words are coming out of years of experince and experiment, so thank you so much for sharing your valuable mindset, so respected it is

I always thinking of the next generation who will be the main buyers and developers of the market in next 5-10 years

They were born and raised by computers, they think and act different and most important they spend money different, in next 20 years they will run the main part of the market(s)

25-30 years ago computers changed the world forever, maybe we should wait for the childern of computers to see the next revolution.

In the end of my thoughts I just know that I really don't know

For sure it did not. I knew this 25 years ago when I developed HCA

Garry thank you so much for your time and response.

I appreciate sharing the information, So good to know that HCA don't show errors in this case

But still Labs are wrong about many other proportions, including this one

I would go for a grading system base on scores rather than words like what GIA(AGS) do, HCA scores are worthy and I like it although more numerical scores will lead to more precise decisions.

Thanks for participating

 

[Serg]

Once, I tried to find the optimal proportions for the classic round brilliant cut. Many have worked on this, and many will likely continue to do so. Therefore, I want to explain my current position on both the benefits of such work and why the goal is unattainable.Studying human perception of the optical properties of diamonds is undoubtedly very useful when based on the round brilliant cut (RBC). RBC has several advantages for this purpose, for example:

1. There is a well-known solution for Optical Performance.
2. It is easy to cut with high precision.
3. The perception is minimally influenced by differences in the evaluation of form beauty, unlike in fancy cuts where the shape of the girdle significantly distracts consumers.
4. The orientation of the cut is practically unimportant during consumer surveys.

However, verifying the correctness of the theory and predicting the optical properties of cuts is better done with fancy diamonds, as they are less influenced by cultural biases.

I disagree with the notion that we cannot find an optimal round cut because we lack the tools for it. The problem is not with the tools but with the fundamental impossibility of such a task. There is no optimal round cut for the same reason that there is no optimal or best food. There is no ideal food not only for all people but even for one person. Depending on mood, previous meals, company, and season, people choose different foods. Good restaurants have to periodically change their menu, otherwise, regular customers stop coming.

Perception is very subjective. What is better: one large fire flash or two small ones with the same total area as the large flash? Each consumer has their own threshold size of the flash, preferring one large flash at times and two smaller ones at other times. No one can indicate the ideal size of a fire flash because it varies not only among different consumers but also because consumers prefer variety in flashes.

We have long been able to accurately predict the brilliance and fire of new cut designs, those that have never been cut before, but this does not mean we know which cut is better for consumers.

Neither developers nor laboratories should decide which cut is better for consumers. This should be decided by the consumers themselves.

Our task is to create beautiful cuts and tools that simplify the creation of beautiful cuts and their selection by consumers.

 

[Texas Leaguer]

@Texas Leaguer Could you please tell us your valuable opinion, is this stone a possible competitor for ACA? How would "Sarin" grade such a stone?

Hello @V_sh,
First let me thank you for sparking an interesting discussion! In this time of major change in the diamond business, it is worthwhile to challenge the status quo and think outside the box. Sometimes our preconceptions are validated, but sometimes a new path forward comes into view.

In answer to your first question of me, I would say that any design is a possible competitor for our diamond brand provided enough people like it. And I don't say that to be flippant. Many years ago one of the pioneers of the super ideal niche developed a brand around the concept of maximum light return. The EightStar was a precision cut round with tweaked girdle facets designed to eliminate virtually all of the light leakage that resulted from normal indexing. So, theoretically this removal of approximately 5% of standard leakage would be superior to the diamonds being offerred by the competition. They were exceptionally well crafted diamonds for the time, and they had their adherents. Whiteflash actually experimented with this innovation ourselves.
But an interesting thing happened over time, and I will credit the pricescope community for providing us the necessary feedback to understand how this 'innovation' played in the real world. Surprisingly, many people (knowlegeable enthusiasts aka pro-sumers) did not like the look of the diamond, and preferred an ideal cut with standard indexing with more light leakage!

It turns out that a small amount of very well distributed leakages around the crown adds enough bits of contrast to accentuate scintillation and the perception of brilliance.

So my point is that facet designs that may appear perfect in theory, or even on light performance images, might or might not be embraced by consumers. Judging from the ASET image posted, if that is an accurate representation of your design, it does appear to be deficient in high angle light return. But until you get it in front of consumers, particularly those with a trained eye, you don't know what you have.

As an aside, I have been shopping for sconces recently. And the thought struck me that your design, drawing so much low angle light, might look really lovely in a room fitted out with bright sconces. Seriously.

 

[0-0-0]

@V_sh Based on my comparisons of round brilliant cuts with similar proportions, I can only say with certainty that I prefer cuts with higher degrees of optical symmetry and crisper patterning.

I haven’t seen one with the proportions you mention in person, but based on the videos of MSSRBC15 and MSSRBC17 on Cutwise, I suspect I would prefer MSSRBC15 as I generally like to see bigger flashes.

 

[V_sh]

Once, I tried to find the optimal proportions for the classic round brilliant cut. Many have worked on this, and many will likely continue to do so. Therefore, I want to explain my current position on both the benefits of such work and why the goal is unattainable.Studying human perception of the optical properties of diamonds is undoubtedly very useful when based on the round brilliant cut (RBC). RBC has several advantages for this purpose, for example:

1. There is a well-known solution for Optical Performance.
2. It is easy to cut with high precision.
3. The perception is minimally influenced by differences in the evaluation of form beauty, unlike in fancy cuts where the shape of the girdle significantly distracts consumers.
4. The orientation of the cut is practically unimportant during consumer surveys.

However, verifying the correctness of the theory and predicting the optical properties of cuts is better done with fancy diamonds, as they are less influenced by cultural biases.

I disagree with the notion that we cannot find an optimal round cut because we lack the tools for it. The problem is not with the tools but with the fundamental impossibility of such a task. There is no optimal round cut for the same reason that there is no optimal or best food. There is no ideal food not only for all people but even for one person. Depending on mood, previous meals, company, and season, people choose different foods. Good restaurants have to periodically change their menu, otherwise, regular customers stop coming.

Perception is very subjective. What is better: one large fire flash or two small ones with the same total area as the large flash? Each consumer has their own threshold size of the flash, preferring one large flash at times and two smaller ones at other times. No one can indicate the ideal size of a fire flash because it varies not only among different consumers but also because consumers prefer variety in flashes.

We have long been able to accurately predict the brilliance and fire of new cut designs, those that have never been cut before, but this does not mean we know which cut is better for consumers.

Neither developers nor laboratories should decide which cut is better for consumers. This should be decided by the consumers themselves.

Our task is to create beautiful cuts and tools that simplify the creation of beautiful cuts and their selection by consumers.

Thank you so much for your time and guidance, so precious it is.

I remember the first time I watched Vladyslav Yavorskyy polishing an expensive huge Sapphire just by holding it in his hand with a non-automatic wheel just based on experience and the look of the stone. (the old method is still working)

Also, I remember you discussed that the Hope Diamond cut is a really well-crafted one although no 3D modeling could be done that time. (3D model supports the old method)

And then I see the fancy cuts of Ramon Tesoro and a level of accuracy that seems almost impossible for diamond cutting. (VERY exact calculations and new fancy cuts are working)

Then I look at Tolkowsky's wrong calculations when he wrote his book at the age of 19, and see people call him the most famous name of the diamond cutting. (SO wrong calculations and old cuts are still working)



all of these make me feel like the new methods and fancy cuts are not really desired and the wrong old ways are still working as long as we are not deep enough in this new fancy world.

The good thing about the undiscovered deep is that nobody knows about it; Fortunately, Cutwise gonna help us understand undiscovered things better

An old expression says:
Everybody knows everything (Which means the knowledge does not belong to individuals but the whole society)

and this is why I like to ask questions mostly weird ones, So thanks for your patience and kindness

 

[V_sh]

Hello @V_sh,
First let me thank you for sparking an interesting discussion! In this time of major change in the diamond business, it is worthwhile to challenge the status quo and think outside the box. Sometimes our preconceptions are validated, but sometimes a new path forward comes into view.

In answer to your first question of me, I would say that any design is a possible competitor for our diamond brand provided enough people like it. And I don't say that to be flippant. Many years ago one of the pioneers of the super ideal niche developed a brand around the concept of maximum light return. The EightStar was a precision cut round with tweaked girdle facets designed to eliminate virtually all of the light leakage that resulted from normal indexing. So, theoretically this removal of approximately 5% of standard leakage would be superior to the diamonds being offerred by the competition. They were exceptionally well crafted diamonds for the time, and they had their adherents. Whiteflash actually experimented with this innovation ourselves.
But an interesting thing happened over time, and I will credit the pricescope community for providing us the necessary feedback to understand how this 'innovation' played in the real world. Surprisingly, many people (knowlegeable enthusiasts aka pro-sumers) did not like the look of the diamond, and preferred an ideal cut with standard indexing with more light leakage!

It turns out that a small amount of very well distributed leakages around the crown adds enough bits of contrast to accentuate scintillation and the perception of brilliance.

So my point is that facet designs that may appear perfect in theory, or even on light performance images, might or might not be embraced by consumers. Judging from the ASET image posted, if that is an accurate representation of your design, it does appear to be deficient in high angle light return. But until you get it in front of consumers, particularly those with a trained eye, you don't know what you have.

As an aside, I have been shopping for sconces recently. And the thought struck me that your design, drawing so much low angle light, might look really lovely in a room fitted out with bright sconces. Seriously.

Hi Bryan,

First, I hope you will be out of trouble soon healthy and strong.

Thanks for sharing your precious knowledge and your great kindness, that means a lot.

For sure you are right about new designs, the whole market should like it and not only experts or sellers; I'm so happy to know this exact example that you mentioned which I wasn't aware of and I'll read and study it definitely.

This cut is not my design, it's based on Octonus experiments and is a part of their MSS project and this exact stone is MSS17
This is just an example to show some of the problems in the cut grading system: even if a cut is performing well it will be mentioned as a "bad" cut by Pioneer Labs if it's not in the box.

In this exact example, MSS17 performs almost as well as ACA or a little bit better but it won't be certified as 000/3EX cut by GIA.

Surely you are right, maybe customers don't prefer MSS17 over ACA, and may not be profitable for cutters to prefer MSS17
But we are suppressing any diversity that is out of the wrong charts of pioneer Labs, So there will be no cutter or designer to really go out of his way to try and investigate other things out of the box.

So how do we know that there is not a better-performance cut (better say, group of cuts) that is more preferred by customers when Labs makes the whole world afraid of anything "Out of the Box"?? (I'm not talking only about RBC)

I've read Tolkowsky's book (pages 80-94) about 15 times and also done Tolkowsky's calculation specifically for Main Crown about 6 times, with different methods

BUT the correct answer for His Method (Which is also wrong because it's 2D, not 3D) is 37.8349° and this angle has nothing to do with 34.5°. (even if we count for 15° of head shadow that he didn't, the answer will be 36.3636°)

So it means we still believe in 1) a wrong 2D method 2) which was calculated mathematically wrong 3) by a 19 years old guy in 1918 who was not from the Tolkowsky family but also from the Kaplan family so his true name is Marcel Kaplan

my quick answer is that if you tell the customers the truth about Tolkowsky and his wrong calculations, will they still be willing to buy a 40.75 | 34.50 diamond?

@Serg @Garry H (Cut Nut) I really like to know your opinions also.

If you tell this Light Physics story from the Diamond market to pioneers of Physics science they will be shocked and laugh as hard as they can.

A so-called scientific organization (GIA) that owns a scientific journal is still publishing cut-grading charts based on wrong calculations and the wrong method of Tolkowsky, and the whole world is still talking about the famous Tolkowsky and his non-mathematical sweetline.


I wish we had Mr. Al Gilbertson in the forum to help us (maybe just me) better understand this

Also, I only found two online sources that tried to cover Tolkowsky's errors and they did the calculations again WRONG.

P.S. Maybe Tolkowsky was not wrong, I suspect that he may have done false data creation to support the angles that cutters working in his stepdad's factory found to be practical. (just a marketing thing for some data based on experience, not mathematics)

 

[V_sh]

@V_sh Based on my comparisons of round brilliant cuts with similar proportions, I can only say with certainty that I prefer cuts with higher degrees of optical symmetry and crisper patterning.

I haven’t seen one with the proportions you mention in person, but based on the videos of MSSRBC15 and MSSRBC17 on Cutwise, I suspect I would prefer MSSRBC15 as I generally like to see bigger flashes.

I have the same taste as you, I think you mean more Scintillation by crisper pattern, which I like too.

So let me tell you something, I found some beautiful standard RBC on the Cutwise platform with a highly symmetrical pattern and higher Scintillation than the accepted regular H&A, and guess what? they are out of 3EX/000 boxes and do perform really amazingly.

@Serg here we have a possible customer for a brand that introduces a RBC with higher Scintillation, so for example tell us why Paul Hung should put effort and design and do marketing for a standard RBC that has more Scintillation (and customers would love it) as long as GIA won't grade that cut 3EX/000??? why should @Karl_K put effort into designing cuts that are out of the box but perform awesomely?
Why shouldn't we at first solve the problem with the vast possible varieties of symmetrical and asymmetrical RBC which owns 70% of the market and instead search for other possible weird shape cuts??

In my opinion, it's not all about fancy cuts, small changes, or "Planned Asymmetries" that you mentioned in your article can make thousands of different RBCs as the simplest example and the best-selling available in the market.

@0-0-0 would you buy a 57-Facets RBC with an exactly planned and calculated asymmetry with high Scintillation if GIA grades it EX-G-G and costs you 20% higher because of the design? would other customers like it also?

My answer is no because customers will think: why should I pay for something that is not as good as 3EX and also pay 20% higher? and no one will buy it from me if I want to change it for a better one?

@Garry H (Cut Nut) why should customers buy an asymmetrical well-performance RBC that looks better in their mind, when we tell them the best RBC under ideal-scope should have these 8 arrows??


P.S. I think of those million-dollar post-modern arts (real ones) and about us discussing why the GIA grading system won't let artists think out of nonmathematical boxes in the charts.

This is a real exact chart worth mentioning from Sergey's article (although even Sergey himself knows this chart has deficiencies, which is inevitable) but at least it's better than GIA's

Yellow parts represent groups of diamonds with high optical performance and a positive trade off for cutting (not wasting too much material)

34.50 | 40.75 is not yellow

 

[Texas Leaguer]

I don't think that the conservative nature of the diamond industry and reluctance to think outside the box is the fault of the laboratories. They provide a service to the trade and to the public that reflects the realities of the customers they serve. Economics drives the ship, and that could be seen in the mediocre to poor makes that dominated the market for decades. And was the reason GIA was so slow to come out with a real cut grading system. And when they did, it was a broad and forgiving one because they couldn't undermine the value of billions of dollars worth of existing inventory.

The manufacturers largely continued their age-old practice of cutting for weight, rather than trying to make the most beautiful diamonds, because of the economics that favored doing so. But with new knowlege (and marketing efforts) around precision cutting for beauty, consumers are demanding more from their merchants and thus from laboratories, giving "pioneer" labs an opportunity to add value to the market and to gain traction.

I think we can expect much more innovation as lab grown diamonds have proliferated and the cost of experimentation is now essentially a non-factor for manufacturers and diamond designers. This in turn will provide new marketing opportunities for merchants.

We are already seeing trends that indicate conumers have a more diverse pallette for shapes and facet arrangements than previously thought. For example, there are far more oval and radiant sales happening than ever before, not just in lab grown, but it is carrying over to natural diamonds as well.

We may be witnessing the dawning of a new world in diamond design and diamond diversity. But don't underestimate the power of the status quo to moderate the trajectory!

 

[Karl_K]

It is a waste of time doing design work on rounds they are latched up tight in their box. There is no room for creativity in the design or the market. The very design locks everything together in one place.

As far as new designs or better performing proportions of existing cuts a lot of producers would like to have it... If its free.
Ask a reasonable price and the interest drops to 0.

 

[Garry H (Cut Nut)]

Bryan -some comments in BOLD thru your excellent post:

I don't think that the conservative nature of the diamond industry and reluctance to think outside the box is the fault of the laboratories. You rather contradict this through your comments Bryan. They provide a service to the trade and to the public that reflects the realities of the customers they serve. Economics drives the ship, and that could be seen in the mediocre to poor makes that dominated the market for decades. And was the reason GIA was so slow to come out with a real cut grading system. Is this a case that is the fault of labs that claim to protect consumers Bryan? And when they did, it was a broad and forgiving one because they couldn't undermine the value of billions of dollars worth of existing inventory. Again Bryan?

I would add that the way GIA conducted their surveys biased toward those deeper cuts that enabled manufacturers to continue cutting for weight.

The manufacturers largely continued their age-old practice of cutting for weight, rather than trying to make the most beautiful diamonds, because of the economics that favored doing so. Supported by GIA But with new knowlege (and marketing efforts) around precision cutting for beauty, consumers are demanding more from their merchants and thus from laboratories, giving "pioneer" labs an opportunity to add value to the market and to gain traction. As the primary developer of the 4C's, surley that should have been GIA's role?

I think we can expect much more innovation as lab grown diamonds have proliferated and the cost of experimentation is now essentially a non-factor for manufacturers and diamond designers. This in turn will provide new marketing opportunities for merchants.

We are already seeing trends that indicate consumer's have a more diverse pallette for shapes and facet arrangements than previously thought. For example, there are far more oval and radiant sales happening than ever before, not just in lab grown, but it is carrying over to natural diamonds as well.

We may be witnessing the dawning of a new world in diamond design and diamond diversity. But don't underestimate the power of the status quo to moderate the trajectory!

Bryan and Karl's next post - I want someone to fund a cut design competition. @Serg and a couple of us played with the idea a decade + ago - we have some plans.
I mentioned the idea in the Seeing the Light Webinar - IGI as the leading lab should step up and support it.
I will be bringing it up in Vegas in 2 weeks.

 

[V_sh]

and that could be seen in the mediocre to poor makes that dominated the market for decades. And was the reason GIA was so slow to come out with a real cut grading system.

and the cost of experimentation is now essentially a non-factor for manufacturers and diamond designers.

We are already seeing trends that indicate conumers have a more diverse pallette for shapes and facet arrangements than previously thought.

We may be witnessing the dawning of a new world in diamond design and diamond diversity. But don't underestimate the power of the status quo to moderate the trajectory!

Thank you so much, Bryan

So great to know your precious opinion and appreciate for sharing your valuable knowledge, it's so helpful.

I hope we will see Whitefalsh in the new design world also, I really like your business and how you do it, especially your informative website.

It is a waste of time doing design work on rounds they are latched up tight in their box. There is no room for creativity in the design or the market. The very design locks everything together in one place.

As far as new designs or better performing proportions of existing cuts a lot of producers would like to have it... If its free.
Ask a reasonable price and the interest drops to 0.

Thank you so much for your valuable opinion and for participating.

Yeah, exactly Karl I mean the same,
and why should you or any other designer do free designs for a producer? how is that even possible?
the one who charges nothing for a design is the one who has put no effort into it.

The producer needs more diversity in end products but he still knows 70% of the market belongs to RBC and no space for creativity in RBC, so a new fancy cut should share 30% of the market with at least 10 already established fancy cuts.
Not him and not the designer would gamble on less than 1% of the market that the new design may occupy after looong years.

about the round, I know what you mean, for sure fancies can be more creative and diverse, but there are still many good RBC varieties that the market is aware of and still can't be worked on, the same thing for many kinds of Fancies.

would Royal Asscher pay you a reasonable price if you design a better Asscher cut?
Not seem possible in my mind

I would add that the way GIA conducted their surveys biased toward those deeper cuts that enabled manufacturers to continue cutting for weight.

Bryan and Karl's next post - I want someone to fund a cut design competition. @Serg and a couple of us played with the idea a decade + ago - we have some plans.
I mentioned the idea in the Seeing the Light Webinar - IGI as the leading lab should step up and support it.
I will be bringing it up in Vegas in 2 weeks.

Yeah Garry,

This kind of thing I expect from leaders of the market, is an amazing idea.

Thanks for the valuable decision

 

[Garry H (Cut Nut)]

Thank you so much, Bryan

So great to know your precious opinion and appreciate for sharing your valuable knowledge, it's so helpful.

I hope we will see Whitefalsh in the new design world also, I really like your business and how you do it, especially your informative website.




Thank you so much for your valuable opinion and for participating.

Yeah, exactly Karl I mean the same,
and why should you or any other designer do free designs for a producer? how is that even possible?
the one who charges nothing for a design is the one who has put no effort into it.

The producer needs more diversity in end products but he still knows 70% of the market belongs to RBC and no space for creativity in RBC, so a new fancy cut should share 30% of the market with at least 10 already established fancy cuts.
Not him and not the designer would gamble on less than 1% of the market that the new design may occupy after looong years.

about the round, I know what you mean, for sure fancies can be more creative and diverse, but there are still many good RBC varieties that the market is aware of and still can't be worked on, the same thing for many kinds of Fancies.

would Royal Asscher pay you a reasonable price if you design a better Asscher cut?
Not seem possible in my mind



Yeah Garry,

This kind of thing I expect from leaders of the market, is an amazing idea.

Thanks for the valuable decision

Karl has already designed the best ever Asscher variant!

 

[V_sh]

Karl has already designed the best ever Asscher variant!

I did not know really
congrats @Karl_K

Would you please share your experience with us? If possible.

So his words about the producers that wouldn't pay for an amazing design, comes from a direct experience.

 

[smitcompton]

Hi,

I just want to thank you all. I have actually learned from this discussion and so enjoyed it. The genuine politeness and sharing ideas on here has impressed me. So, I thank you all. I admit I will keep IGI on my radar. This is a 5 star thread for me.

Annette

 

[smitcompton]

Hi,

You know who should sponsor a contest for new variations in diamond cut. ===You guessed it. DeBeers. They could use some good publicity now. Three top prizes so cutters have a chance at winning some money. It has to have an incentive.

DeBeers has been selected.

Annette

 

[Garry H (Cut Nut)]

Hi,

You know who should sponsor a contest for new variations in diamond cut. ===You guessed it. DeBeers. They could use some good publicity now. Three top prizes so cutters have a chance at winning some money. It has to have an incentive.

DeBeers has been selected.

Annette

Annette De Beers will soon be sold or floated. So no decisions there for quite a while.
Also their main focus is natural diamond and sponsoring a synthetic diamond competition might not be their thing!

 

[Serg]

I would add that the way GIA conducted their surveys biased toward those deeper cuts that enabled manufacturers to continue cutting for weight.

The regions of equivalent Optical Performance have very complex curvilinear shapes in the coordinate system defined by the cut parameters. Moreover, these regions are multiply connected. In other words, they don't look like a football field but rather like a mountain range, with peaks and valleys. Often, the value of Optical Performance changes significantly and rapidly with slight changes in a parameter. Therefore, a detailed map in this multi-dimensional space, even for Optical Performance EX-VG, would need to contain billions of measurements for a round cut and immeasurably more for fancy cuts. This is unrealistic and impractical with current technology.

Thus, laboratories that work with cut parameters have to coarsely approximate this grid. For example, instead of using 0.1 degrees for the crown and pavilion angles, they use 0.5 or 0.25 degrees, 1% for the table diameter, and ignore the variation in the azimuths of the facets. This inevitably leads to both false positive and false negative errors.
They won't be able to minimize both errors simultaneously due to the limitations of the parameter-based method. Methods based on evaluating Optical Performance through videos also have limitations, but the MaxMin of these two errors is significantly smaller compared to parameter-based methods.

AGS chose a strategy to minimize false positives, while GIA minimized false negatives. It appears that GIA's approach was more correct, and I support it because laboratories should not block beautiful cuts (GIA's approach to minimizing false negatives blocks far fewer beautiful cuts than AGS's approach).

At the same time, I understand the opposite viewpoint that consumer protection requires minimizing false positives (AGS's approach). However, true consumer protection is not possible if certification blocks industry innovation. Therefore, AGS's strategy was doomed to fail. There were heated debates about this 10-15 years ago on PriceScope, and I was heavily criticized by Ideal Cut supporters.

For a certification system to be strategically sustainable, it must either minimize false negatives or use an approach where both types of errors are sufficiently small. Since GIA and IGI do not have such technology, they are forced to limit themselves to certifying RBC and minimizing false negatives.

Talks about grading only being done to allow cutters to make steep cuts distract from the real issues and tasks. Personally, I don't gain any benefit from cutting diamonds with deep pavilions, but I believe that stones with P41.2Cr34.5 have noticeably better performance than P40.2Cr34.5.
The notion that cutters want to maximize yield and GIA accommodates them, while consumers only want to buy beautiful cuts, is overly simplistic and diverts the discussion into an unconstructive area instead of addressing the pressing issues of the industry. Some consumers want to buy the best, while others want something cheaper and bigger. The concept of "the best" is also not universal. For example, I prefer diamonds with a deeper pavilion, while Harry likes shallow diamonds.

Who would want a lab to decide for them what food is tasty and ideal, and even the same for everyone? Isn't it better to create conditions for restaurants so they can delight us with a variety of cuisines?



"A false positive is when a scientist determines something is true when it is actually false (also called a type I error). A false positive is a “false alarm.” A false negative is saying something is false when it is actually true (also called a type II error)."

 

[V_sh]

AGS chose a strategy to minimize false positives, while GIA minimized false negatives. It appears that GIA's approach was more correct, and I support it because laboratories should not block beautiful cuts (GIA's approach to minimizing false negatives blocks far fewer beautiful cuts than AGS's approach).

Thanks for your time and assistance, you helped me a lot in this further understanding, Sergey.

The problem is that new Labs like GCAL are doing the wrong old thing again and the new grading approaches from old labs like IGI are still based on the wrong old thing.

There is no willingness to change in the market.

billions of measurements for a round cut and immeasurably more for fancy cuts. This is unrealistic and impractical with current technology.

I DO agree with you, but because we can't count for "billions of measurements" it means we should count for only 3 measurements? so no matter among Labs which one is "Bad" and which one is the "Worst" still none of them are good (in this field)

What's your idea about a grading chart based on scores to be published by Octonus? will this be helpful or just make things more complicated?

 

[Garry H (Cut Nut)]

What's your idea about a grading chart based on scores to be published by Octonus? will this be helpful or just make things more complicated?

And importantly what's the solution to providing cutting guidance to manufacturers Sergey for billions of combinations?

 

[Garry H (Cut Nut)]

This is from my forthcoming book:


Consider the scale of a data base of proportions for an emerald cut grading system. I asked Jasper Paulsen to help me with the math for an emerald cut. This requires more than 6,000,000,000,000,000,000 data points. That does not account for corner facet lengths and angles.
Jasper Paulsen is a mathematician interested in diamonds. Jasper improved Tolkowsky’s “ideal” round proportions at www.folds.net.
It could take a century or more to build and validate a database to establish five cut quality grade boundaries. Building a system to enable diamond cutters to plan the most efficient model for individual rough diamonds is then the next complex step.

 

[Serg]

And importantly what's the solution to providing cutting guidance to manufacturers Sergey for billions of combinations?

For the purposes of cutting guidance, there is not much difference between 1,000 and 10,000 combinations, as the difference in yield will be insignificant. The difference in results between 10,000 and 100,000 combinations is unlikely to be noticeable in the final yield, provided these combinations are correctly selected. To select the correct 10,000 combinations, we currently check at least 10,000,000. However, for the purposes of these tasks, it is not critical if we miss some good combinations, as they can always be added later.

Therefore, the parameter-based approach and 3D models are quite effective for cutters, unlike in the case of laboratory tasks. For cutters, a false negative error does not pose a risk. False positive errors are practically non-existent if the proportions are correctly verified. However, what works well for cutters is not very applicable for laboratory tasks.

 

[Garry H (Cut Nut)]

For the purposes of cutting guidance, there is not much difference between 1,000 and 10,000 combinations, as the difference in yield will be insignificant. The difference in results between 10,000 and 100,000 combinations is unlikely to be noticeable in the final yield, provided these combinations are correctly selected. To select the correct 10,000 combinations, we currently check at least 10,000,000. However, for the purposes of these tasks, it is not critical if we miss some good combinations, as they can always be added later.

Therefore, the parameter-based approach and 3D models are quite effective for cutters, unlike in the case of laboratory tasks. For cutters, a false negative error does not pose a risk. False positive errors are practically non-existent if the proportions are correctly verified. However, what works well for cutters is not very applicable for laboratory tasks.

So Sergey, based on say a rectangular clean LGD block of say 14x10x7mm you could propose emerald cut proportions that a skilled manufacturer can produce an exceptional 5ct stone?
(There is no need to fight for yeild with the LGD material)

 

[Karl_K]

So Sergey, based on say a rectangular clean LGD block of say 14x10x7mm you could propose emerald cut proportions that a skilled manufacturer can produce an exceptional 5ct stone?
(There is no need to fight for yeild with the LGD material)

No, for the same reason most everyone who tried to cut ags0 step cuts based on a list of numbers failed without a lot of r&d. Most just gave up. You have a bunch of rows that float in 3d space. Change the corners or the l/w slightly changes everything else also.
It would take more than just proportion numbers to set up a process that can consistently produce great step cuts.