Diamond fire vs spectra colour

[Serg]

I was there for your oral and poster in 2006, with enthusiasm (was it really 14 years ago?). All of those materials are a great resource for those of us who know how to find them. But how are you reaching others?

I've trained jewelry pros around the USA for a dozen years. During corona I've done a series of diamond and gemstone webinars with average attendance of 100+ pros per session. Candidly, topics like those we're discussing remain completely unknown until I introduce them. To career jewelers.

[/QUOTE

I am not a teacher.
I am the researcher and developer. I am member of big highly skilled team that develops software, hardware , writes articles, does presentations, helps many manufactures to improve diamond cuts and process flow.
Our products like Diamcalc , Dibox and now Cutwise help many professionals to understand diamond cut, design new nice cuts, improve old designs.
other products as Helium, Galahad help produce diamond according CAD designs.
our articles had bean read many other researchers and developers, and also some teachers .
Also I train few teachers and am creating diamond beauty workshop, sometimes I prepare presentations ( for example for GIA symposiums ).
I have a dream to combine all these materials in one book.
Many my works are under NDA and I can not describe it here .
Also last 20 years I am fight against destructive diamond industry concepts like: Ideal cut, Forever.
see for example our presentation

“Diamond Impression: Key to Sustainable Competitiveness”

 

[diagem]

I am not a teacher.
I am the researcher and developer. I am member of big highly skilled team that develops software, hardware , writes articles, does presentations, helps many manufactures to improve diamond cuts and process flow.
Our products like Diamcalc , Dibox and now Cutwise help many professionals to understand diamond cut, design new nice cuts, improve old designs.
other products as Helium, Galahad help produce diamond according CAD designs.
our articles had bean read many other researchers and developers, and also some teachers .
Also I train few teachers and am creating diamond beauty workshop, sometimes I prepare presentations ( for example for GIA symposiums ).
I have a dream to combine all these materials in one book.
Many my works are under NDA and I can not describe it here .
Also last 20 years I am fight against destructive diamond industry concepts like: Ideal cut, Forever.
see for example our presentation

“Diamond Impression: Key to Sustainable Competitiveness”

Excellent presentation by Janak, this is the first I have seen that is touching human senses and an early attempt to categorize it.

Just afraid its way too advanced for your average professional (audience).., unfortunately basic cut education is still required. I am sure some can agree with me on that.

 

[John P]

I am not a teacher. I am the researcher and developer.

My belief is your R&D could use more voice.

Thanks for linking the presentation.

This graphic at 17:00 is the kind of thing I'm talking about which needs more voice. I realize it relates to Hi-Vi designs in the presentation, but even connecting it to top commercial specimens would be instructive for jewelers and for consumers in-store, as a visual tutorial (correlating it with NeedScope model is a different thing).



I developed a similar graphic for a course I give on evolution of RBC (only) 1700-2020, showing fire versus brightness goals over time, due to changes in tools, lighting and economics.

Also last 20 years I am fight against destructive diamond industry concepts like: Ideal cut, Forever.

I'd suggest the main obstacles to "several summits" are (1) too little education, and (2) too much economics.

(1) At 9:00 Janak talks about cut-related terms. But most jewelers have never heard of IS or ASET. With terms like Ideal they're taught to remember catch phrases. They don't understand underlying classification criteria. That prevents meaningful analysis and evaluation of even basic MRB varieties. "Several summits" is a beautiful concept. But meaningful criteria-discussion, interpretation and differentiation isn't even happening with one summit right now.

(2) Economics: Miners sell according to highest bids on 3Cs. They don't care what shape or cut-quality is made. That motivates producers to buy and cut to the heaviest EX or VG they can make. That's what is on the market. It's not consumers or jewelers deciding the vast, vast majority of output will be deep MRBs.

I believe lack of education (which is 3Cs based) and economics (which is 3Cs based) are the main obstacles to those championing the 4th C of cut-craftsmanship - across all summits.

 

[John P]

Excellent presentation by Janak, this is the first I have seen that is touching human senses and an early attempt to categorize it.

Just afraid its way too advanced for your average professional (audience).., unfortunately basic cut education is still required. I am sure some can agree with me on that.

I was writing my post when you posted.

As you can see, I did. And I do.

 

[Garry H (Cut Nut)]

Sergey - I think you cheated on the 43.6 stone because the 39.8 pavilion would not look the same if you also rotated it.
Sergey and John - if you remove my ray tracing images that have been stolen from some online sellers and affiliates from those images then 20% might drop to 1 or 2%. I produced those ray traces for Ideal-scope 18 or 19 years ago.
Sergey - you have done so much that is not known to improve diamond quality. I know. But John is correct - the communication is not cutting through. I really believe if you focused on the capacity you have to grade the transparency of diamonds - that would become an international deal and market changer. The instant you do there will be some very strong competitors who will also quickly develop their own systems and it will become
Yoram aka DiaGem - Sergey and Janak info does cut through at the very top of the manufacturing market. The leaders in manufacturing always attend their talks. The marketing folk - John is right.

 

[Serg]

Excellent presentation by Janak, this is the first I have seen that is touching human senses and an early attempt to categorize it.

Just afraid its way too advanced for your average professional (audience).., unfortunately basic cut education is still required. I am sure some can agree with me on that.

Yoram , we can not give basic cut educational in 20 min presentation, It is impossible .
The basic cut education we give in 6-8 hours the workshop .
Page about diamond cut

 

[Serg]

Sergey - I think you cheated on the 43.6 stone because the 39.8 pavilion would not look the same if you also rotated it.
Sergey and John - if you remove my ray tracing images that have been stolen from some online sellers and affiliates from those images then 20% might drop to 1 or 2%. I produced those ray traces for Ideal-scope 18 or 19 years ago.
Sergey - you have done so much that is not known to improve diamond quality. I know. But John is correct - the communication is not cutting through. I really believe if you focused on the capacity you have to grade the transparency of diamonds - that would become an international deal and market changer. The instant you do there will be some very strong competitors who will also quickly develop their own systems and it will become
Yoram aka DiaGem - Sergey and Janak info does cut through at the very top of the manufacturing market. The leaders in manufacturing always attend their talks. The marketing folk - John is right.

Garry,
we rotate all 5 diamonds in exactly same way and we show for each diamond the facet had been used for ray tracing. did you check the full page ?
it is not online course , it is demo pages from our offline course . Offline we show several rays paths for each diamond sample,


For NailHead diamond we explain what the reason Nailhead phenomena is head obscuration instead Leakage . we do not compare NeailHead diamond with the shallow diamond P39.8.
The shallow diamond P39.8 we compare with the deep diamond P41.8
where did you find cheating here?

on the next page we compare Shallow P 40.2 with Deep P41.4 ( +/- 0.6 degree from P 40.
Do you see any cheating here also?

Sweet Line in Round Diamonds – docs

Consider two dimensional Ca-Pa variations of the round parameters

docs.cutwise.com

 

[Garry H (Cut Nut)]

What amount of rotation Sergey? I only checked one other stone (I just posted) and could not replicate your ray.
i think you need to check them.

 

[Serg]

What amount of rotation Sergey? I only checked one other stone (I just posted) and could not replicate your ray.
i think you need to check them.

"
In this demonstration we tilt diamond by 10 degrees. Very shallow diamond and “Nail head” reflects the same area in space during this rotation. It means that these stones reflection of observer’s head is very stable. And even during rotation they will remain black creating ”Dead zones” effect (areas in diamond that always remain black). This results very bad performance of these stones.

Shallow diamond change ray path angle by 1.7 degrees. Tolkowsky displays 4.3 degrees ray angle variation. And Deep stone has highest value among selected stones.

Generally high flash speed during the stone rotation is positive as it allows diamond to produce flashes more often.
"

Garry, did you read full text on the page

Ray Path in Round Diamond – docs

How stereo defines round diamond performance

docs.cutwise.com

?

 

[AV_]

Shallow diamond change ray path angle by 1.7 degrees. Tolkowsky displays 4.3 degrees ray angle variation. And Deep stone has highest value among selected stones.

digressing

@Garry H (Cut Nut) this reminds me of your experiment - www, telling of how taste depends on the intuition that diamonds are not still; certainly my bias,

panta rei.

 

[Serg]

My belief is your R&D could use more voice.

Thanks for linking the presentation.

This graphic at 17:00 is the kind of thing I'm talking about which needs more voice. I realize it relates to Hi-Vi designs in the presentation, but even connecting it to top commercial specimens would be instructive for jewelers and for consumers in-store, as a visual tutorial (correlating it with NeedScope model is a different thing).



I developed a similar graphic for a course I give on evolution of RBC (only) 1700-2020, showing fire versus brightness goals over time, due to changes in tools, lighting and economics.

John, Did you check the WorkShop Description ?




"Communication in a diamond shop may start with a dynamic chart, similar to the one presented here. Consumer sees that diamond can be beautiful in different ways and can make different types of impressions. Salesperson clarifies the role of the lighting and follows the consumer's preferred left- or right- brain side language to select the most personality-matching diamond option.

Why the technologies and the course are needed There are unaddressed opportunities in the diamond market. New technologies withdraw the existing obstacles.

• Diamond sales stagnate in developed markets. Diamonds become less and less attractive in new generations. Repeat purchases are jeopardized by absence of high-performing product diversity and novelty.
• Even at the growing markets diamond appearance and beauty are not effectively promoted to consumers; current communications are lab-report-numbers-based and refer to the left side of the brain predominantly, so emotional bonding with product is quite limited. This makes diamonds uncompetitive vs other luxury goods in a long-term. This is a crucial gap especially because research reports more and more women are becoming decision makers in diamond purchases and women are more image- and emotion- driven than men.
• Currently salesperson is not able to demonstrate diamond beauty to consumer in 5-10 minutes. It is not easy to justify difference in diamonds' performance either. Now this takes a lot of time and requires high qualification of sales personnel because diamond is very small and consumer typically can not spot fine details (D/IF, H&A, for example). Thus, currently it is salesperson who makes the choice and convinces client. This often results in unconfidence, mistrust and lack of emotional bonding with diamond.
• Most of the resources that the diamond industry invests are used for making a first sale (usually an engagement diamond), which is a very inefficient business model. There is no general know-how to increase the repeating purchases which is the most lucrative approach.
• There are consumers who are interested in more than one diamond but there is no alluring offerings, just bigger round stones.
• The efficient market growth and highest return on promotion investments will be reached when the ratio of second (and all subsequent) purchases to first-time purchase increases.

What addresses the diamond market opportunities

There is a spectrum of means to combine targeting the opportunities.

It is necessary to help customers to enjoy the first purchase experience and product so much that they will be interested to return for a second/next diamond. It will be possible if the product and the selection process are intriguing, pleasant and novel:
"

 

[diagem]

Yoram , we can not give basic cut educational in 20 min presentation, It is impossible .
The basic cut education we give in 6-8 hours the workshop .
Page about diamond cut

...so talking high academic language to an audience that barely understand cut basics is not very efficient.

The twenty minute talk by Janak was very interesting to me and IMO can be separated into a scientific and an emotional subject as both are pretty novel, the latter more so.

Matching human senses to the different play-of-lights options can be surprisingly more interesting to the professional retailer as it makes more sense and requires a different type of knowledge base, more general.

No doubt though this is an avenue that needs to be further researched and conquered eventually. Such schemes might even change the way diamonds are graded in the future as well, just a thought...

 

[AV_]

Matching human senses to the different play-of-lights options

This is a highly enjoyable trip!

 

[Garry H (Cut Nut)]

"
In this demonstration we tilt diamond by 10 degrees. Very shallow diamond and “Nail head” reflects the same area in space during this rotation. It means that these stones reflection of observer’s head is very stable. And even during rotation they will remain black creating ”Dead zones” effect (areas in diamond that always remain black). This results very bad performance of these stones.

Shallow diamond change ray path angle by 1.7 degrees. Tolkowsky displays 4.3 degrees ray angle variation. And Deep stone has highest value among selected stones.

Generally high flash speed during the stone rotation is positive as it allows diamond to produce flashes more often.
"

Garry, did you read full text on the page

Ray Path in Round Diamond – docs

How stereo defines round diamond performance

docs.cutwise.com

?

Sergey I would like to see a face up graphic showing where the entry rays are striking the table. I do not think that is clear.

 

[Garry H (Cut Nut)]

I had some offline discussions with John P regarding my frustration with those simplified and very wrong ray path traces that have annoyed me for 40 years.
Someone mentioned there are several images online that are accurate. Almost all are mine from the Ideal-scope reference chart

Reference Chart Ideal Scope Images - Ideal Scope

ideal-scope.com

Note Copyright 2003.

Because of this thread I decided to ask a freind to make an explanation video:

 

[Serg]

Sergey I would like to see a face up graphic showing where the entry rays are striking the table. I do not think that is clear.

Garry,

This information is available on page https://docs.cutwise.com/blog/ray-path-in-round-diamond.

Better to read the page from beginning .

Also I had published it here in post from 9th May.
I attached it again.

 

[Garry H (Cut Nut)]

Why are the entry points different for 43.6? I can see no explanation for different entry points in the ray paths?
I would not call a stone with pavilion angle below 44 degrees a nail head.
Please explain why the ray paths are not the same in each set Sergey?
For example that part of the Shallow stone can perform very well if you send the ray through the same target.

 

[Serg]

Why are the entry points different for 43.6? I can see no explanation for different entry points in the ray paths?
I would not call a stone with pavilion angle below 44 degrees a nail head.
Please explain why the ray paths are not the same in each set Sergey?
For example that part of the Shallow stone can perform very well if you send the ray through the same target.

• A diamond is bad if it has significant nail head area . Are you agree this such statement ?
• it is reasonable to show nearest ( from Tolkovsky proportions) diamonds with nail head phenomena . is it logical ?
• The nearest shallow diamond has neailhead main facets .The nearest deep diamond has nailhead halves. Is it correct?

Why have we discuss only about nail head main facets? Is the deep diamond with nail head halves good for you?

 

[Garry H (Cut Nut)]

Sergey I simply want to know why you did not use the same modeling for all examples - was it just a mistake?
Or was there a purpose?

 

[Serg]

Sergey I simply want to know why you did not use the same modeling for all examples - was it just a mistake?
Or was there a purpose?

Garry,
I gave an answer to your question. If you want to understand my answer you need to answer my questions.

 

[PM83]

Hi everyone,

I have a question as I tried to search up the forum but I haven’t find anything about it.

Do you guys have any pictures, videos or links showing the difference between a diamond showing lots of spectra colour and a diamond showing fire?

In particular I’m interested in those diamonds showing lots of rainbow colours when in indirect sunlight.

Does it happen more often when the diamond is colourless vs it has more yellow?

Does it just depend on the cut or is there a specific diamond quality that influences it?

thanks a lot in advance!


D colour, super ideal cut diamond in indirect sunlight.

I’m glad I found this thread because I’d noticed the spectra colours on my diamond as well, especially in shaded outdoor lighting. I will attach a couple photos and a video. When I first saw this I thought maybe I had Received a moissanite instead of a lab diamond. I have checked inscription and it all matches with the cert so I know it is indeed a lab diamond, but I was a bit taken aback as I had previously thought that diamonds would be more “bright and white”. The video quality is not as good as the one saved into my phone and it’s not quite capturing all of the rainbows, and in person it is just gorgeous, especially in this lighting.

Photos:


Video:

 

[Eeveepenny]

I’m glad I found this thread because I’d noticed the spectra colours on my diamond as well, especially in shaded outdoor lighting. I will attach a couple photos and a video. When I first saw this I thought maybe I had Received a moissanite instead of a lab diamond. I have checked inscription and it all matches with the cert so I know it is indeed a lab diamond, but I was a bit taken aback as I had previously thought that diamonds would be more “bright and white”. The video quality is not as good as the one saved into my phone and it’s not quite capturing all of the rainbows, and in person it is just gorgeous, especially in this lighting.

Photos:


Video:

Wow that’s beautiful! Can you please provide the specs of your diamond?

 

[Gemly]

The color show in indirect light is what ultimately sold me on my 3.2 ct.

 

[PM83]

Wow that’s beautiful! Can you please provide the specs of your diamond?

Thank you! and it is 1.56 ct, G, Vs2, Triple excellent. Table: 57, crown: 35, pavilion: 40.8, depth: 61.2

 

[PM83]

The color show in indirect light is what ultimately sold me on my 3.2 ct.

Absolutely gorgeous this reminds me of how my diamond looks in indirect lighting, almost as if it is glowing. Enjoy that gorgeous 3 ct!

 

[Eeveepenny]

Thank you! and it is 1.56 ct, G, Vs2, Triple excellent. Table: 57, crown: 35, pavilion: 40.8, depth: 61.2

Same specs as mine! Mine doesn’t have fire like that though

 

[PM83]

Same specs as mine! Mine doesn’t have fire like that though

Your diamond looks gorgeous from your profile photo I love the arrows, it looks like it is beautifully cut. Have you looked at it in all lighting? If you haven’t yet, try looking at it underneath a tree! Lighting makes a big difference! For example, this is a photo of my diamond still in indirect Sun light, in the same spot but it was taken earlier in the day and appears more bright, whereas my first photos in my above post, the sun was setting, and it is more fiery than bright. (This was also my old 4 prong setting). The last photo was taken at night time, with my crappy lights at home (no fire)

 

[OoohShiny]

Cool pics over the last few posts, thank you for posting!

 

[Big Fat Facets]

John, Did you check the WorkShop Description ?




"Communication in a diamond shop may start with a dynamic chart, similar to the one presented here. Consumer sees that diamond can be beautiful in different ways and can make different types of impressions. Salesperson clarifies the role of the lighting and follows the consumer's preferred left- or right- brain side language to select the most personality-matching diamond option.

Why the technologies and the course are needed There are unaddressed opportunities in the diamond market. New technologies withdraw the existing obstacles.

• Diamond sales stagnate in developed markets. Diamonds become less and less attractive in new generations. Repeat purchases are jeopardized by absence of high-performing product diversity and novelty.
• Even at the growing markets diamond appearance and beauty are not effectively promoted to consumers; current communications are lab-report-numbers-based and refer to the left side of the brain predominantly, so emotional bonding with product is quite limited. This makes diamonds uncompetitive vs other luxury goods in a long-term. This is a crucial gap especially because research reports more and more women are becoming decision makers in diamond purchases and women are more image- and emotion- driven than men.
• Currently salesperson is not able to demonstrate diamond beauty to consumer in 5-10 minutes. It is not easy to justify difference in diamonds' performance either. Now this takes a lot of time and requires high qualification of sales personnel because diamond is very small and consumer typically can not spot fine details (D/IF, H&A, for example). Thus, currently it is salesperson who makes the choice and convinces client. This often results in unconfidence, mistrust and lack of emotional bonding with diamond.
• Most of the resources that the diamond industry invests are used for making a first sale (usually an engagement diamond), which is a very inefficient business model. There is no general know-how to increase the repeating purchases which is the most lucrative approach.
• There are consumers who are interested in more than one diamond but there is no alluring offerings, just bigger round stones.
• The efficient market growth and highest return on promotion investments will be reached when the ratio of second (and all subsequent) purchases to first-time purchase increases.

What addresses the diamond market opportunities

There is a spectrum of means to combine targeting the opportunities.

It is necessary to help customers to enjoy the first purchase experience and product so much that they will be interested to return for a second/next diamond. It will be possible if the product and the selection process are intriguing, pleasant and novel:
"

Most of this is WAY WAY WAY over my head but THIS is AMAZING & most FASCINATING!!!

i've always felt that diamond scintillation, fire, facet patterning has a personality and traits that appeal to certain people and not others on an emotional, intrinsic level. thats why some of us gravitate to certain cuts and make.

Before encountering this pictorial diagram. I noticed how some diamond makes/cuts offer a stressing or stimulating quality where other cuts have a soothing calming nurturing quality.

I realize what i am expressing is completely emotional and not scientific. I don't know enough to speak on science.

i understand why when all i knew of diamonds was mrb. i didn't get it. I didn't know what all fuss what about. I've had and enjoyed some really nice ones. Then i discovered for myself the oec, omb, emerald cut and i was HOOKED!!
it was a personality character type of thing...