The story of the Hope Diamond in 3D models

[Serg]

The story of the Hope Diamond in 3D models.On the right side of the screen, you can select the model, on the left side, rotate it.I would be glad to hear suggestions on how to improve this format of storytelling about historical diamonds.

Hope Diamond

hope-diamond.cutwise.com

 

[Karl_K]

Someone needs to offer some LGD replicas/models of the Hope.
Start around 5ct and go up.

 

[Garry H (Cut Nut)]

Someone needs to offer some LGD replicas/models of the Hope.
Start around 5ct and go up.

Scott Sucher from Museum Diamonds does this. I hope to get him on here to get involved as he had Sergey arrange for scanning some plaster and lead castings that led to the proofs that the T = F = Hope

 

[Garry H (Cut Nut)]

Scott did 90% of the work here. We met when he bought DiamCalc to be able to use the model that was built from the scan in Antwerp.

https://www.gia.edu/gems-gemology/spring-2009-french-blue-hope-diamond-farges

 

[Museum Diamonds]

The story of the Hope Diamond in 3D models.On the right side of the screen, you can select the model, on the left side, rotate it.I would be glad to hear suggestions on how to improve this format of storytelling about historical diamonds.

Hope Diamond

hope-diamond.cutwise.com

Nice job in representing the three diamonds. Interesting comparing todays standards (cut, spread, brilliance, etc) to historical work.

 

[Museum Diamonds]

In response to Karl
Scaling diamonds is difficult to maintain the necessary optics. The FB has about 84 facets which is appropriate for a stone of 69 cts. Place the same number and the same pattern on a 5 ct stone and it will look dramatically different, way too overcut and losing the reflection pattern. I have reduced the pattern for a stone about 10 carats to preserve the star in the pavilion but other reflections suffer. Still brilliant but different. Same issue for scaling up.

 

[V_sh]

The story of the Hope Diamond in 3D models.On the right side of the screen, you can select the model, on the left side, rotate it.I would be glad to hear suggestions on how to improve this format of storytelling about historical diamonds.

Hope Diamond

hope-diamond.cutwise.com

Dear Sergey,

Thanks for sharing your precious project, I like it and will follow its progress.

I have a few points about it that may help you, although I'm sure you are aware of these better than me.

The most precious information that your website can provide to me is the light performance in the scientific/numerical format, I'm sure there are difficulties in providing light performance scores for fancy colors but that seems greatly interesting to me to compare light performance before and after recut.

I'm sure "Scintillation Score" will be super helpful for fancy colors if you could provide it in the future; my past experiences which can be learned in your "Light–Spectrum Demo" project also, prove that the Scintillation of the diamond design enormously impacts the intensity of the color in fancy diamonds; so what a great investigation it will be if we could compare the light performance of famous diamonds before and after recut.

At this point, I'm very interested in this project if you add data of a famous white diamond before and after recut or simply its light performance scores after cutting, then we can discuss and investigate the craftmanship related to a certain time in history or a certain artisan.

I definitely can imagine how hard it is to scan or gather exact data about cut designs of famous diamonds, So I appreciate your efforts.

You may generously do me a favor and consider adding famous white diamonds so we can check their interesting light performance scores.

Best of luck

 

[Serg]

Dear Sergey,

Thanks for sharing your precious project, I like it and will follow its progress.

I have a few points about it that may help you, although I'm sure you are aware of these better than me.

The most precious information that your website can provide to me is the light performance in the scientific/numerical format, I'm sure there are difficulties in providing light performance scores for fancy colors but that seems greatly interesting to me to compare light performance before and after recut.

I'm sure "Scintillation Score" will be super helpful for fancy colors if you could provide it in the future; my past experiences which can be learned in your "Light–Spectrum Demo" project also, prove that the Scintillation of the diamond design enormously impacts the intensity of the color in fancy diamonds; so what a great investigation it will be if we could compare the light performance of famous diamonds before and after recut.

At this point, I'm very interested in this project if you add data of a famous white diamond before and after recut or simply its light performance scores after cutting, then we can discuss and investigate the craftmanship related to a certain time in history or a certain artisan.

I definitely can imagine how hard it is to scan or gather exact data about cut designs of famous diamonds, So I appreciate your efforts.

You may generously do me a favor and consider adding famous white diamonds so we can check their interesting light performance scores.

Best of luck

Although counting the number of Scintillation flashes is relatively easy, comparing Scintillation across different cuts according to human perception is a significant challenge. The Scintillation pattern in emerald, pear, and princess cuts is entirely different. The final perception is influenced not only by the number of flashes and their distribution but also by the brightness of the cut. Unlike Brilliancy and Fire, it is very difficult to separate Scintillation from various negative optical effects observed in diamonds. Therefore, we have not yet made the results of our Scintillation metric publicly available, as they could mislead consumers. Instead, we are preparing tools to gather and analyze information from a large number of consumers on how they assess Optical performance, especially Scintillation, across different cuts. It is important not only to count the number of flashes but also to obtain real information about which cuts consumers prefer. The current inability to representatively ascertain consumer opinions is hindering the development of cuts and technologies for creating beautiful cuts.

Regarding Scintillation in the Hope and French Blue diamonds, I fail to understand its relevance for evaluating these historical stones. Firstly, there is practically none present in them, as the patterns of these cuts mainly consist of large slow virtual facets, which is typical for most diamonds cut before the 19th century. I have seen very few antique cuts with small fast virtual facets creating Scintillation. Secondly, these diamonds have strong absorption, and their beauty is influenced much more by the pattern of color, its saturation, rather than by the flashes. And most importantly, the primary value of The Hope diamond lies not in its Optical performance but in its history

It is interesting to note that despite The Hope being cut almost 200 years ago and having a highly asymmetrical shape, it has virtually no leakage except for on the culet. This speaks to the highest level of skill of the cutter and their good understanding of diamond optics at a time when there was no possibility to computer model the work due to the complexity of its asymmetrical design.

 

[Serg]

Nice job in representing the three diamonds. Interesting comparing todays standards (cut, spread, brilliance, etc) to historical work.

The Hope has spread +14.5%,
French blue spread is -1.8%

 

[V_sh]

Although counting the number of Scintillation flashes is relatively easy, comparing Scintillation across different cuts according to human perception is a significant challenge. The Scintillation pattern in emerald, pear, and princess cuts is entirely different. The final perception is influenced not only by the number of flashes and their distribution but also by the brightness of the cut. Unlike Brilliancy and Fire, it is very difficult to separate Scintillation from various negative optical effects observed in diamonds. Therefore, we have not yet made the results of our Scintillation metric publicly available, as they could mislead consumers. Instead, we are preparing tools to gather and analyze information from a large number of consumers on how they assess Optical performance, especially Scintillation, across different cuts. It is important not only to count the number of flashes but also to obtain real information about which cuts consumers prefer. The current inability to representatively ascertain consumer opinions is hindering the development of cuts and technologies for creating beautiful cuts.

Regarding Scintillation in the Hope and French Blue diamonds, I fail to understand its relevance for evaluating these historical stones. Firstly, there is practically none present in them, as the patterns of these cuts mainly consist of large slow virtual facets, which is typical for most diamonds cut before the 19th century. I have seen very few antique cuts with small fast virtual facets creating Scintillation. Secondly, these diamonds have strong absorption, and their beauty is influenced much more by the pattern of color, its saturation, rather than by the flashes. And most importantly, the primary value of The Hope diamond lies not in its Optical performance but in its history

It is interesting to note that despite The Hope being cut almost 200 years ago and having a highly asymmetrical shape, it has virtually no leakage except for on the culet. This speaks to the highest level of skill of the cutter and their good understanding of diamond optics at a time when there was no possibility to computer model the work due to the complexity of its asymmetrical design.

Thanks a lot Sergey for the information.

I think that this won't be the last famous/historical diamond you worked on, so my opinion is not only about fancy colors or the Hope diamond, I think that comparing famous diamonds in terms of light performances can be cool (of course I mean numerical comparison)

There is also a question about this specific diamond, is it possible to have at least a brilliance score for fancy-color diamonds? although ASET image helps a lot

Also, the spread helps a lot, but I think this parameter is more practical for colorless ones and less useful for colored ones; a design may get a higher spread but less color intensity, etc. (for sure I mean it generally not only about this specific diamond)


In the end, I think you've started an exciting journey in the diamond industry and this will help you to increase your reputation in the market, People would greatly trust a company that assesses diamond cuts and qualities in detail and also applies this method of grading for famous diamonds and tell stories about their cut qualities.

I found and know about the big mistakes that Diamond Grading Labs make, their grading systems have many deficiencies, A simple example is that 3EX is a worthless term; Also I asked IGI what their frameworks are to identify a diamond as H&A, what combination of angles or proportions? It seems to me that they don't have an accurate framework for it and I didn't find any, at least HRD and WTOCD say something about grading H&A; Anyway, I think the grading system you started to work on will have fewer problems than others and assessing cut qualities of famous diamonds by your grading system will convince the market to trust you more and more. (Will GIA/AGS apply their EX/VG/G or 000 grading systems to famous diamonds? A BIG NO, because if they do we will see enormous deficiencies in their systems)

The progress of your "famous diamonds performance" project will be exciting for us, and adding more numerical parameters for comparing diamonds will amaze us.

Wish you all the best in your research

 

[Serg]

There is also a question about this specific diamond, is it possible to have at least a brilliance score for fancy-color diamonds? although ASET image helps a lot

Brilliancy can be considered for both Cut and polished diamonds. When calculating Brilliancy for well-cleaned polished diamonds, factors such as material and quality of polishing also influence the result alongside the cut. Therefore, if we compare Brilliancy for polished diamonds with two identical cuts but different colors, such as L and Yellow Intense, the Brilliancy of the Yellow Intense polished diamond will be significantly lower than its L color counterpart. So, how do we use Brilliancy for Fancy color polished diamonds in such cases? If we consider Brilliancy for cut, the result for Dark-colored stones will be even more misleading. What significance does Brilliancy grade for Cut have for black diamonds or milky polished diamonds? Hence, the primary characteristic of Fancy color diamonds is their color, specifically Chroma, which includes brightness and saturation. Of course, this evaluation should not only consider the average value of Chroma but also how evenly the color is distributed across the diamond, its stability during rotations, and the presence of Window and Dead zones in the cut design. Just as coffee and tea are both beverages, but the quality rating system for coffee is not suitable for evaluating tea, and vice versa. The same applies to sandwiches and pastries, wine and coffee, Colorless and fancy color diamonds

 

[Serg]

Also, the spread helps a lot, but I think this parameter is more practical for colorless ones and less useful for colored ones; a design may get a higher spread but less color intensity, etc. (for sure I mean it generally not only about this specific diamond)

Spread indicates how visually large a diamond appears. For example, the French Blue 71 ct looks its weight because its surface area is equal to that of a 70 ct RBC. However, The Hope 45 ct appears like a 53 ct RBC. Buyers desire diamonds that appear larger, not just heavier. Therefore, Spread is important for all types of diamonds regardless of their color, design, or flaws. If the diamond industry actively utilized Spread to determine discounts and premiums per carat, there would be fewer poorly cut diamonds with critical masses, such as 1.00 ct. More details about Spread can be found in the video

 

[V_sh]

Brilliancy can be considered for both Cut and polished diamonds. When calculating Brilliancy for well-cleaned polished diamonds, factors such as material and quality of polishing also influence the result alongside the cut. Therefore, if we compare Brilliancy for polished diamonds with two identical cuts but different colors, such as L and Yellow Intense, the Brilliancy of the Yellow Intense polished diamond will be significantly lower than its L color counterpart. So, how do we use Brilliancy for Fancy color polished diamonds in such cases? If we consider Brilliancy for cut, the result for Dark-colored stones will be even more misleading. What significance does Brilliancy grade for Cut have for black diamonds or milky polished diamonds? Hence, the primary characteristic of Fancy color diamonds is their color, specifically Chroma, which includes brightness and saturation. Of course, this evaluation should not only consider the average value of Chroma but also how evenly the color is distributed across the diamond, its stability during rotations, and the presence of Window and Dead zones in the cut design. Just as coffee and tea are both beverages, but the quality rating system for coffee is not suitable for evaluating tea, and vice versa. The same applies to sandwiches and pastries, wine and coffee, Colorless and fancy color diamonds

Thanks for your time Sergey, that means a lot.

For sure I do agree with you about the difference between Brilliance in L and Yellow intense color diamonds even if they have the same size and design, and that's why I mentioned that I know it's difficult to have light performance scores for fancy colors; But that's not really impossible, is it?

For Brilliance and Fire in colorless diamonds, you have an index like MSS13 and you compare all the colorless ones with it (like making a thermometer for the first time you gonna put indexes like melting ice and boiling water and divide the in-between space into X parts); So the problem for colored ones is that you need index and for sure I understand that it's a massive work to make indexes for every color unless it's possible to do it virtually. How?

Let's say we select MSS13 as the index again but this time we give it an exact color (Hue, Saturation, Tone) and ask the computer to calculate its Brilliance, and the score for example will be 0.80 (In comparison to colorless MSS13 which is 1.00) so we can now have an index and we can compare a real stone with that specific color to the virtual MSS13 with the same color.

For this exact work color grading like what GIA does is worth less and it will be a challenge for Octonus and Lexus to make their own color grading chart that won't be impacted by the mass of stone or the front look and design of the stone (e.g. we should be able to determine the color of each stone as if it's a 1x1x1mm cube)
GIA grades stones based on how intense their color looks from the front side; so 2 stones that have 2 different sizes and designs and are cut from a single unicolor rough gonna have two different color intensities based on what GIA does.

In the end, as a customer, I'll ask Octonus to tell me the Brilliance of my 0.5 ct Pear cut yellow intense diamond, they will find the color properties of my stone as if it was 1x1x1mm cube and give this exact color to the index cut design (e.g. MSS13) with the same size (0.5ct) and they give me the comparison between my stone and the index stone.

You are much more experienced than me in this, do you think it's possible?

For sure I do know the difficulties of doing this like what would happen to Green diamonds or those with color zoning and the massive difficulty of selecting an index cut design and .......

But is that impossible? or there was not a tough guy in history looking to really do this?

I know about much more complex grading systems in physics and biology and a light-performance grading system for colored diamonds is not a big deal.

I respect you because you are not a businessman you're a researcher; a businessman will find worthy projects and buy them; a researcher puts years of his life into doing something that others said it's impossible.

 

[V_sh]

Spread indicates how visually large a diamond appears. For example, the French Blue 71 ct looks its weight because its surface area is equal to that of a 70 ct RBC. However, The Hope 45 ct appears like a 53 ct RBC. Buyers desire diamonds that appear larger, not just heavier. Therefore, Spread is important for all types of diamonds regardless of their color, design, or flaws. If the diamond industry actively utilized Spread to determine discounts and premiums per carat, there would be fewer poorly cut diamonds with critical masses, such as 1.00 ct. More details about Spread can be found in the video

Yeah, I know about the spread and its importance, and I agree with you. also thanks for sharing the video.

It's simple, if I give you a colorless diamond at first glance your brain sees its size
But if I give a colored one you look at the color and then its size


Should I choose this pear because it has a good spread?

Pear, 0.38ct, FI OY, SI1, EX, VG, STR, +1.5%

Pear, 0.38ct, FI OY, SI1, EX, VG, STR, +1.5%

cutwise.com

or this oval with a bad spread but a better light performance?

Oval, 0.30ct, FI OY, VS2, EX, VG, MED, -22.5%

Oval, 0.30ct, FI OY, VS2, EX, VG, MED, -22.5%

cutwise.com

as a first-time buyer, how should I know if the cut quality of oval is better than pear? do we need a light performance score for these two stones?

and I think your index for the spread in the colored diamonds should not be RBC; 70% of sold colorless diamonds are RBC but this is not true for colored diamonds.

Most colored diamonds are cut into fancy shapes optimized to have high Scintillation. and why should we compare them to standard RBC which has low Scintillation?
I guess this is not a scientific comparison

Am I right or you may convince me about my fault?

 

[Serg]

Thanks for your time Sergey, that means a lot.

For sure I do agree with you about the difference between Brilliance in L and Yellow intense color diamonds even if they have the same size and design, and that's why I mentioned that I know it's difficult to have light performance scores for fancy colors; But that's not really impossible, is it?

For Brilliance and Fire in colorless diamonds, you have an index like MSS13 and you compare all the colorless ones with it (like making a thermometer for the first time you gonna put indexes like melting ice and boiling water and divide the in-between space into X parts); So the problem for colored ones is that you need index and for sure I understand that it's a massive work to make indexes for every color unless it's possible to do it virtually. How?

Let's say we select MSS13 as the index again but this time we give it an exact color (Hue, Saturation, Tone) and ask the computer to calculate its Brilliance, and the score for example will be 0.80 (In comparison to colorless MSS13 which is 1.00) so we can now have an index and we can compare a real stone with that specific color to the virtual MSS13 with the same color.

For this exact work color grading like what GIA does is worth less and it will be a challenge for Octonus and Lexus to make their own color grading chart that won't be impacted by the mass of stone or the front look and design of the stone (e.g. we should be able to determine the color of each stone as if it's a 1x1x1mm cube)
GIA grades stones based on how intense their color looks from the front side; so 2 stones that have 2 different sizes and designs and are cut from a single unicolor rough gonna have two different color intensities based on what GIA does.

In the end, as a customer, I'll ask Octonus to tell me the Brilliance of my 0.5 ct Pear cut yellow intense diamond, they will find the color properties of my stone as if it was 1x1x1mm cube and give this exact color to the index cut design (e.g. MSS13) with the same size (0.5ct) and they give me the comparison between my stone and the index stone.

You are much more experienced than me in this, do you think it's possible?

For sure I do know the difficulties of doing this like what would happen to Green diamonds or those with color zoning and the massive difficulty of selecting an index cut design and .......

But is that impossible? or there was not a tough guy in history looking to really do this?

I know about much more complex grading systems in physics and biology and a light-performance grading system for colored diamonds is not a big deal.

I respect you because you are not a businessman you're a researcher; a businessman will find worthy projects and buy them; a researcher puts years of his life into doing something that others said it's impossible.

Of course, technically it's possible, but the harm from such an approach outweighs the benefits. AGS once used a similar approach to provide Optical Performance grades for colorless fancy cuts. They compared princess cuts with princess cuts, ovals with ovals. As a result, some ovals received the highest AGS grade of 0, misleading consumers because despite the AGS 0 grade, these ovals had much worse performance than RBC AGS 0, and consumers were unaware of the performance of these ovals. The same thing will happen if your approach is applied to colored stones. Some Fancy Dark stones will receive a relatively high Brilliancy grade, even though all the brilliance will be created only by reflections from the crown facets. Not every technology, not even every correct piece of information, has a positive impact on market development. When developing new methodologies, it's necessary to try not to harm the market, taking into account the interests of both consumers and cutters and sellers. The approach you proposed will work against the interests of consumers, although it will provide additional technical information.

 

[V_sh]

Of course, technically it's possible, but the harm from such an approach outweighs the benefits. AGS once used a similar approach to provide Optical Performance grades for colorless fancy cuts. They compared princess cuts with princess cuts, ovals with ovals. As a result, some ovals received the highest AGS grade of 0, misleading consumers because despite the AGS 0 grade, these ovals had much worse performance than RBC AGS 0, and consumers were unaware of the performance of these ovals. The same thing will happen if your approach is applied to colored stones. Some Fancy Dark stones will receive a relatively high Brilliancy grade, even though all the brilliance will be created only by reflections from the crown facets. Not every technology, not even every correct piece of information, has a positive impact on market development. When developing new methodologies, it's necessary to try not to harm the market, taking into account the interests of both consumers and cutters and sellers. The approach you proposed will work against the interests of consumers, although it will provide additional technical information.

Thank you so much for your time, Sergey

You convinced me about its issues, although, I'm sure that by making the grading system more complex this problem would be solved but again your statement about consumers not going to like that will be true.

I conclude that complex grading systems are desired by consumers who are more patient and educated than today.
At this time some information like the amount of Brillianteering is out of patience of most consumers.

I greatly appreciate you for sharing this valuable information.