95-98% accurate color grading machines.

[diagem]

Date: 5/25/2009 4:27:26 AM
Author: Serg

re:So I think we are pretty much in understanding at present that human intervention is needed when grading the color [and clarity] of Diamonds...

Diagem,

We near the point where human and machine accuracies for grading color are similar. ( Fluorescence is problem for both approach, because clear rules for grading is absent)
Evolution line for color grading : ''Bi-line or Tri-line colorimeters'', ''transmission absorption spectrum'', ''Absorption spectrum and exact 3d models''.

First two technology based on Statistic and can not account color pattern in diamond, accuaracy depends from positions sample and difference between theoretical or real 3d models had been used for Statistic data base and 3D model object what you want grade .
Third color grading technology less depends from Statistic databased but need much more complex model to model human vision.
Third technology could be ready for industry use in few years.

So I understand third technology is the future...?
To tackle fluorescence problem you just need agreed rules? Like for example translating and combining intensity and color of fluo. to spectral absorption?
What about shapes, square vs. elongated?
Brn-grey hues will be based on human vision model?

Is third technology based on face-up only or is body color part of the equation?

 

[Serg]

Date: 5/25/2009 6:25:45 AM
Author: DiaGem

Date: 5/25/2009 4:27:26 AM

Author: Serg


re:So I think we are pretty much in understanding at present that human intervention is needed when grading the color [and clarity] of Diamonds...


Diagem,


We near the point where human and machine accuracies for grading color are similar. ( Fluorescence is problem for both approach, because clear rules for grading is absent)

Evolution line for color grading : ''Bi-line or Tri-line colorimeters'', ''transmission absorption spectrum'', ''Absorption spectrum and exact 3d models''.


First two technology based on Statistic and can not account color pattern in diamond, accuaracy depends from positions sample and difference between theoretical or real 3d models had been used for Statistic data base and 3D model object what you want grade .

Third color grading technology less depends from Statistic databased but need much more complex model to model human vision.

Third technology could be ready for industry use in few years.

So I understand third technology is the future...?

To tackle fluorescence problem you just need agreed rules? Like for example translating and combining intensity and color of fluo. to spectral absorption?

What about shapes, square vs. elongated?

Brn-grey hues will be based on human vision model?


Is third technology based on face-up only or is body color part of the equation?

re:So I understand third technology is the future...?

We use this technology for fancy color diamonds several years ( for color optimization) .
There is necessary adaptation this technology for colorless diamonds ( for color optimizations and color prediction ) COlor grading is other issue, but its possible too

re:What about shapes, square vs. elongated? Is third technology based on face-up only or is body color part of the equation?

Why do you think , 3D model is necessary for third technology ?

re:Brn-grey hues will be based on human vision model?
1) Brn-grey diamonds have usually spectrum with infrared absorption( yellow diamonds has zero absorption in infrared ). So simple correct of base line ( for absorption spectrum ) does not work( O think, it is important reason why 1st technology has big error for such type spectrum). for other type correction is possible but much more expensive yet.
2) Are sure what Brown is Hue? Some humans consider Brown as Dark Yellow

 

[Garry H (Cut Nut)]

Date: 5/25/2009 6:25:45 AM
Author: DiaGem

Date: 5/25/2009 4:27:26 AM
Author: Serg

re:So I think we are pretty much in understanding at present that human intervention is needed when grading the color [and clarity] of Diamonds...

Diagem,

We near the point where human and machine accuracies for grading color are similar. ( Fluorescence is problem for both approach, because clear rules for grading is absent)
Evolution line for color grading : ''Bi-line or Tri-line colorimeters'', ''transmission absorption spectrum'', ''Absorption spectrum and exact 3d models''.

First two technology based on Statistic and can not account color pattern in diamond, accuaracy depends from positions sample and difference between theoretical or real 3d models had been used for Statistic data base and 3D model object what you want grade .
Third color grading technology less depends from Statistic databased but need much more complex model to model human vision.
Third technology could be ready for industry use in few years.

So I understand third technology is the future...?
To tackle fluorescence problem you just need agreed rules? Like for example translating and combining intensity and color of fluo. to spectral absorption?
What about shapes, square vs. elongated?
3D models is the answer DG
Brn-grey hues will be based on human vision model?

Is third technology based on face-up only or is body color part of the equation?

 

[diagem]

Date: 5/25/2009 7:51:06 AM
Author: Serg

Date: 5/25/2009 6:25:45 AM
Author: DiaGem

Date: 5/25/2009 4:27:26 AM

Author: Serg


re:So I think we are pretty much in understanding at present that human intervention is needed when grading the color [and clarity] of Diamonds...


Diagem,


We near the point where human and machine accuracies for grading color are similar. ( Fluorescence is problem for both approach, because clear rules for grading is absent)

Evolution line for color grading : ''Bi-line or Tri-line colorimeters'', ''transmission absorption spectrum'', ''Absorption spectrum and exact 3d models''.


First two technology based on Statistic and can not account color pattern in diamond, accuaracy depends from positions sample and difference between theoretical or real 3d models had been used for Statistic data base and 3D model object what you want grade .

Third color grading technology less depends from Statistic databased but need much more complex model to model human vision.

Third technology could be ready for industry use in few years.

So I understand third technology is the future...?

To tackle fluorescence problem you just need agreed rules? Like for example translating and combining intensity and color of fluo. to spectral absorption?

What about shapes, square vs. elongated?

Brn-grey hues will be based on human vision model?


Is third technology based on face-up only or is body color part of the equation?

re:So I understand third technology is the future...?

We use this technology for fancy color diamonds several years ( for color optimization) .
There is necessary adaptation this technology for colorless diamonds ( for color optimizations and color prediction ) COlor grading is other issue, but its possible too

Possible including taking body color into the equation?

re:What about shapes, square vs. elongated? Is third technology based on face-up only or is body color part of the equation?

Why do you think , 3D model is necessary for third technology ?

3D model will solve accuracy color grading in all shapes?

re:Brn-grey hues will be based on human vision model?
1) Brn-grey diamonds have usually spectrum with infrared absorption( yellow diamonds has zero absorption in infrared ). So simple correct of base line ( for absorption spectrum ) does not work( O think, it is important reason why 1st technology has big error for such type spectrum). for other type correction is possible but much more expensive yet.
2) Are sure what Brown is Hue? Some humans consider Brown as Dark Yellow

Serg..., is there a relation between brown & pink?

 

[Serg]

Date: 5/25/2009 8:09:27 AM
Author: DiaGem

Date: 5/25/2009 7:51:06 AM

Author: Serg

Date: 5/25/2009 6:25:45 AM

Author: DiaGem

Date: 5/25/2009 4:27:26 AM


Author: Serg



re:So I think we are pretty much in understanding at present that human intervention is needed when grading the color [and clarity] of Diamonds...



Diagem,



We near the point where human and machine accuracies for grading color are similar. ( Fluorescence is problem for both approach, because clear rules for grading is absent)


Evolution line for color grading : 'Bi-line or Tri-line colorimeters', 'transmission absorption spectrum', 'Absorption spectrum and exact 3d models'.



First two technology based on Statistic and can not account color pattern in diamond, accuaracy depends from positions sample and difference between theoretical or real 3d models had been used for Statistic data base and 3D model object what you want grade .


Third color grading technology less depends from Statistic databased but need much more complex model to model human vision.


Third technology could be ready for industry use in few years.

So I understand third technology is the future...?


To tackle fluorescence problem you just need agreed rules? Like for example translating and combining intensity and color of fluo. to spectral absorption?


What about shapes, square vs. elongated?


Brn-grey hues will be based on human vision model?



Is third technology based on face-up only or is body color part of the equation?

re:So I understand third technology is the future...?


We use this technology for fancy color diamonds several years ( for color optimization) .

There is necessary adaptation this technology for colorless diamonds ( for color optimizations and color prediction ) COlor grading is other issue, but its possible too


Possible including taking body color into the equation?



re:What about shapes, square vs. elongated? Is third technology based on face-up only or is body color part of the equation?


Why do you think , 3D model is necessary for third technology ?


3D model will solve accuracy color grading in all shapes?


re:Brn-grey hues will be based on human vision model?

1) Brn-grey diamonds have usually spectrum with infrared absorption( yellow diamonds has zero absorption in infrared ). So simple correct of base line ( for absorption spectrum ) does not work( O think, it is important reason why 1st technology has big error for such type spectrum). for other type correction is possible but much more expensive yet.

2) Are sure what Brown is Hue? Some humans consider Brown as Dark Yellow


Serg..., is there a relation between brown & pink?

re:is there a relation between brown & pink?

are you asking about Colors or about reasons such colors in Diamonds?

re:3D model will solve accuracy color grading in all shapes?

Diagem, if somebody give Definition what color is for Arbitrary Shape , 3d model with absorption spectrum will solve problems with accuracy and repeatability for color grading.

The main problem is what Nobody know what color grade is for all shapes.

reossible including taking body color into the equation?

Simply : (Absorption spectrum + diamond size)= body color
Others depend from Color grade definition

 

[diagem]

Date: 5/25/2009 8:32:00 AM
Author: Serg

re:is there a relation between brown & pink?

are you asking about Colors or about reasons such colors in Diamonds?

Reasons or relations? As per my experience in cutting..., there is a relation between the two.

re:3D model will solve accuracy color grading in all shapes?

Diagem, if somebody give Definition what color is for Arbitrary Shape , 3d model with absorption spectrum will solve problems with accuracy and repeatability for color grading.

The main problem is what Nobody know what color grade is for all shapes.

Can the problem be solved via building a data-base? Or is it to scattered?

reossible including taking body color into the equation?

Simply : (Absorption spectrum + diamond size)= body color
Others depend from Color grade definition

So after you get a color grade of the 3D model absorption spectrum of both face up and body..., how would you suggest calculating a combined value?

 

[Serg]

Date: 5/25/2009 9:21:42 AM
Author: DiaGem

Date: 5/25/2009 8:32:00 AM

Author: Serg


re:is there a relation between brown & pink?


are you asking about Colors or about reasons such colors in Diamonds?


Reasons or relations? As per my experience in cutting..., there is a relation between the two.


re:3D model will solve accuracy color grading in all shapes?


Diagem, if somebody give Definition what color is for Arbitrary Shape , 3d model with absorption spectrum will solve problems with accuracy and repeatability for color grading.


The main problem is what Nobody know what color grade is for all shapes.



Can the problem be solved via building a data-base? Or is it to scattered?


reossible including taking body color into the equation?


Simply : (Absorption spectrum + diamond size)= body color

Others depend from Color grade definition

So after you get a color grade of the 3D model absorption spectrum of both face up and body..., how would you suggest calculating a combined value?

Should we combine its?


Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.



''Diagem,
thanks for very good questions. Specially I like "Does a GIA Fancy yellow have the same quantity (body or face-up) color as a Fancy pink or blue?"

There are two "Colors"
1) Body what has strong correlation with absorption spectrum and diamond size. Such "Color" create "Rarity Value" for fancy color diamonds
2) Face-up what depends from absorption spectrum , diamond size AND CUT. Such "Color" create two Values : "Craftsmanship" and Color Performance for Consumer.

Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.

re: if the Diamond shows a genuine ''J-K'' body color (profile) and an ''H'' faceup color..., which is what?? What should the consumer pay for? Who owns the right to call the grade, a GG or the machine?

I do not see any real problem. "Machine" could give grade from any direction. "Machine" even does not need rotate diamond for this /
Expert can not give facet-up consistency grade for colorless diamonds''
https://www.pricescope.com/community/threads/round-table-best-light-conditions-for-diamond-subjective-performance-comparison.115561/page-4

 

[adamasgem]

Date: 5/25/2009 9:36:26 AM
Author: Serg

Date: 5/25/2009 9:21:42 AM
Author: DiaGem

Date: 5/25/2009 8:32:00 AM

Author: Serg


re:is there a relation between brown & pink?


are you asking about Colors or about reasons such colors in Diamonds?


Reasons or relations? As per my experience in cutting..., there is a relation between the two.


re:3D model will solve accuracy color grading in all shapes?


Diagem, if somebody give Definition what color is for Arbitrary Shape , 3d model with absorption spectrum will solve problems with accuracy and repeatability for color grading.


The main problem is what Nobody know what color grade is for all shapes.



Can the problem be solved via building a data-base? Or is it to scattered?


reossible including taking body color into the equation?


Simply : (Absorption spectrum + diamond size)= body color

Others depend from Color grade definition

So after you get a color grade of the 3D model absorption spectrum of both face up and body..., how would you suggest calculating a combined value?

Should we combine its?


Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.



''Diagem,
thanks for very good questions. Specially I like ''Does a GIA Fancy yellow have the same quantity (body or face-up) color as a Fancy pink or blue?''

There are two ''Colors''
1) Body what has strong correlation with absorption spectrum and diamond size. Such ''Color'' create ''Rarity Value'' for fancy color diamonds
2) Face-up what depends from absorption spectrum , diamond size AND CUT. Such ''Color'' create two Values : ''Craftsmanship'' and Color Performance for Consumer.

Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.

re: if the Diamond shows a genuine ''J-K'' body color (profile) and an ''H'' faceup color..., which is what?? What should the consumer pay for? Who owns the right to call the grade, a GG or the machine?

I do not see any real problem. ''Machine'' could give grade from any direction. ''Machine'' even does not need rotate diamond for this /
Expert can not give facet-up consistency grade for colorless diamonds''
https://www.pricescope.com/community/threads/round-table-best-light-conditions-for-diamond-subjective-performance-comparison.115561/page-4

Serg.. you forgot the Certifigate aspect of color grading, especially fancy colors...
The inhomogeneous nature of some diamonds also creates problems when determining, or better said, estimating, the face up "Key" color call, unfortunately, as does the human in the loop $$$$.

 

[Serg]

Date: 5/25/2009 11:57:54 AM
Author: adamasgem

Date: 5/25/2009 9:36:26 AM

Author: Serg

Date: 5/25/2009 9:21:42 AM

Author: DiaGem

Date: 5/25/2009 8:32:00 AM


Author: Serg



re:is there a relation between brown & pink?



are you asking about Colors or about reasons such colors in Diamonds?



Reasons or relations? As per my experience in cutting..., there is a relation between the two.



re:3D model will solve accuracy color grading in all shapes?



Diagem, if somebody give Definition what color is for Arbitrary Shape , 3d model with absorption spectrum will solve problems with accuracy and repeatability for color grading.



The main problem is what Nobody know what color grade is for all shapes.





Can the problem be solved via building a data-base? Or is it to scattered?



reossible including taking body color into the equation?



Simply : (Absorption spectrum + diamond size)= body color


Others depend from Color grade definition

So after you get a color grade of the 3D model absorption spectrum of both face up and body..., how would you suggest calculating a combined value?

Should we combine its?



Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.




''Diagem,

thanks for very good questions. Specially I like ''Does a GIA Fancy yellow have the same quantity (body or face-up) color as a Fancy pink or blue?''


There are two ''Colors''

1) Body what has strong correlation with absorption spectrum and diamond size. Such ''Color'' create ''Rarity Value'' for fancy color diamonds

2) Face-up what depends from absorption spectrum , diamond size AND CUT. Such ''Color'' create two Values : ''Craftsmanship'' and Color Performance for Consumer.


Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.


re: if the Diamond shows a genuine ''J-K'' body color (profile) and an ''H'' faceup color..., which is what?? What should the consumer pay for? Who owns the right to call the grade, a GG or the machine?


I do not see any real problem. ''Machine'' could give grade from any direction. ''Machine'' even does not need rotate diamond for this /

Expert can not give facet-up consistency grade for colorless diamonds''

https://www.pricescope.com/community/threads/round-table-best-light-conditions-for-diamond-subjective-performance-comparison.115561/page-4

Serg.. you forgot the Certifigate aspect of color grading, especially fancy colors...

The inhomogeneous nature of some diamonds also creates problems when determining, or better said, estimating, the face up ''Key'' color call, unfortunately, as does the human in the loop $$$$.

re:Serg.. you forgot the Certifigate aspect of color grading, especially fancy colors...

Are you sure? Why do you think I forgot it? Certifigate helped a lot of Machine color grading

 

[adamasgem]

Date: 5/25/2009 12:51:40 PM
Author: Serg


re:Serg.. you forgot the Certifigate aspect of color grading, especially fancy colors...

Are you sure? Why do you think I forgot it? Certifigate helped a lot of Machine color grading

Serg I meant that tounge in cheek, as I thought you hadn''t mentioned it

You are absolutely right, Certifigate HAS and will continue to help machine color grading, problem is that there are no "real" standards to go by...
I have actually been told in the past, by someone at GIA, that in fancy color diamond grading, the bar from one intensity grade to another was a moving target, like in blues... I think yellows are more easily defined, but pinks and blues and other colors are quite a quandry... and of course, cutters have learned how to intensify the color, as in radiants, to get "lucky" vivid beacuse of the "key" color concept.. But who knows, tomorrow there may be a different "standard", as it appears now there is a lot of shifting so called standards around.

 

[diagem]

Date: 5/25/2009 9:36:26 AM
Author: Serg

Date: 5/25/2009 9:21:42 AM
Author: DiaGem

Date: 5/25/2009 8:32:00 AM

Author: Serg


re:is there a relation between brown & pink?


are you asking about Colors or about reasons such colors in Diamonds?


Reasons or relations? As per my experience in cutting..., there is a relation between the two.


re:3D model will solve accuracy color grading in all shapes?


Diagem, if somebody give Definition what color is for Arbitrary Shape , 3d model with absorption spectrum will solve problems with accuracy and repeatability for color grading.


The main problem is what Nobody know what color grade is for all shapes.



Can the problem be solved via building a data-base? Or is it to scattered?


reossible including taking body color into the equation?


Simply : (Absorption spectrum + diamond size)= body color

Others depend from Color grade definition

So after you get a color grade of the 3D model absorption spectrum of both face up and body..., how would you suggest calculating a combined value?

Should we combine its?


Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.

Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?



''Diagem,
thanks for very good questions. Specially I like ''Does a GIA Fancy yellow have the same quantity (body or face-up) color as a Fancy pink or blue?''

There are two ''Colors''
1) Body what has strong correlation with absorption spectrum and diamond size. Such ''Color'' create ''Rarity Value'' for fancy color diamonds
2) Face-up what depends from absorption spectrum , diamond size AND CUT. Such ''Color'' create two Values : ''Craftsmanship'' and Color Performance for Consumer.

Grading report for fancy color diamonds needs have information about Rarity and Craftsmanship.

re: if the Diamond shows a genuine ''J-K'' body color (profile) and an ''H'' faceup color..., which is what?? What should the consumer pay for? Who owns the right to call the grade, a GG or the machine?

I do not see any real problem. ''Machine'' could give grade from any direction. ''Machine'' even does not need rotate diamond for this /
Expert can not give facet-up consistency grade for colorless diamonds''
https://www.pricescope.com/community/threads/round-table-best-light-conditions-for-diamond-subjective-performance-comparison.115561/page-4

 

[Serg]

Diagem,

re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?

Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?
Same answer is for Color Rarity.

Thanks what you did not ask me, who was first: chicken or egg?

 

[John P]

Date: 5/25/2009 3:26:29 AM
Author: DiaGem
Thanks you (all) guys,

*John P..., can you elaborate a bit more on you mentioning:

'For the record, in the big (consumer) picture, I'm with Strm here.'

Any suggestions how to adapt a new grading model that will be better for consumers?

Oh gosh. Blow it up?

I mean, I love this biz but we're wonky.

Personally, I'm riveted by differences in gemology and craftsmanship... But why do we go and force the invisible on consumers as learning and selling priorities? The first Cs you hear about in stores after carat are color and clarity. Why?? How about starting with what's visible to any viewer: Size (simple) shape (simple) subsets of shape like 60-60 vs Near-Tolk vs Transitional vs Shallow in RB and their performance characteristics. These are visible differences even if color/clarity are the same.

Instead we have a system that divides color, clarity and finish to often-invisible levels (D Flawless can appear identical to F VS when cut the same way) and historically emphasizes these categories to consumers - yet the same system fails to differentiate notable differences in visual character (a nice 60-60 w 85% LH is different to anyone than a nice Transitional w 75% LH)...

Because pricing is driven by "rarity" we have made these color/clarity differences the mainstays in our lab assessments and presentations to consumers. Well I submit these are the trade's priorities, not necessarily the consumer's.

Size? Important! Shape? Important! Visual Character & Performance on the finger? Important! Aren't these all priorities? And while I do think color is certainly important, in my experience a range of color may be acceptable when someone finds the size, shape and performance characteristics they like. Same with clarity.

Obviously I am in D-Z territory above. Go to fancy colors and consumer priorities logically shift.

Sorry, I know I strayed from the topic, but you asked.

 

[diagem]

Date: 5/25/2009 3:42:47 PM
Author: John Pollard

Date: 5/25/2009 3:26:29 AM
Author: DiaGem
Thanks you (all) guys,

*John P..., can you elaborate a bit more on you mentioning:

''For the record, in the big (consumer) picture, I''m with Strm here.''

Any suggestions how to adapt a new grading model that will be better for consumers?

Oh gosh. Blow it up?

I mean, I love this biz but we''re wonky.

Personally, I''m riveted by differences in gemology and craftsmanship... But why do we go and force the invisible on consumers as learning and selling priorities? The first Cs you hear about in stores after carat are color and clarity. Why?? How about starting with what''s visible to any viewer: Size (simple) shape (simple) subsets of shape like 60-60 vs Near-Tolk vs Transitional vs Shallow in RB and their performance characteristics. These are visible differences even if color/clarity are the same.

Instead we have a system that divides color, clarity and finish to often-invisible levels (D Flawless can appear identical to F VS when cut the same way) and historically emphasizes these categories to consumers - yet the same system fails to differentiate notable differences in visual character (a nice 60-60 w 85% LH is different to anyone than a nice Transitional w 75% LH)...

Because pricing is driven by ''rarity'' we have made these color/clarity differences the mainstays in our lab assessments and presentations to consumers. Well I submit these are the trade''s priorities, not necessarily the consumer''s.

Size? Important! Shape? Important! Visual Character & Performance on the finger? Important! Aren''t these all priorities? And while I do think color is certainly important, in my experience a range of color may be acceptable when someone finds the size, shape and performance characteristics they like. Same with clarity.

Obviously I am in D-Z territory above. Go to fancy colors and consumer priorities logically shift.

Sorry, I know I strayed from the topic, but you asked.

So you are saying the trade & labs should prioritize grades based on consumer priority? (Do I understand you correctly?)

 

[strmrdr]

lets face it when you get right down to it diamond grading today is based on smoke and mirrors over marketing.

Anything that don''t remove some of that is not a positive step.

Using the current pricing system upgrading a non-fancy diamonds color grade over body color grade because of cut is fraud in my book.
That is why I warned everyone a few years back that I was going to be calling them out on saying that this cut makes an I like a G.
It does not because the advertised/lab/trade color the price is based on is body color and the illusion of rarity. That I is still an I.

 

[adamasgem]

Date: 5/25/2009 3:41:47 PM
Author: Serg
Diagem,

re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?

Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?
Same answer is for Color Rarity.

Thanks what you did not ask me, who was first: chicken or egg?

The fertilized egg requires a hen and a rooster (or artificicial insemination), or else G-D, nature, evolution, whatever variation on the theme you choose.

Then again you have The Greedy Institute of Arrogance(TM) sticking their nose into the equation, so everything else evolved from their corruptness in grading

 

[adamasgem]

Date: 5/25/2009 4:07:40 PM
Author: strmrdr
lets face it when you get right down to it diamond grading today is based on smoke and mirrors over marketing.

Anything that don''t remove some of that is not a positive step.

Using the current pricing system upgrading a non-fancy diamonds color grade over body color grade because of cut is fraud in my book.
That is why I warned everyone a few years back that I was going to be calling them out on saying that this cut makes an I like a G.
It does not because the advertised/lab/trade color the price is based on is body color and the illusion of rarity. That I is still an I.

Storm You are quite right, depending on the cutting quality, in colorless diamonds , the stone can face up much better than the bodycolor determined by classical pavilion view methods. I have seen K''s face up like H-I''s because of the minimal internal absorption of light (average pathlength through the stone), when compared to normal assymmetrical cutting.

In the same manner, maximizing the pathlength through the stone by carefull cutting, and apriori

knowledge, like with DiamondCalc, can intensify the color in fancy colored diamonds.

 

[John P]

Date: 5/25/2009 4:02:01 PM
Author: DiaGem

So you are saying the trade & labs should prioritize grades based on consumer priority? (Do I understand you correctly?)

I'm saying consumers wouldn't start thinking "D-K" or "FL-VS" unless we as a trade taught them to do so.

A normal person doesn't see a brand new diamond on a friend's finger and think "Ooh, G/H VS2/SI1..." Normally the eye is drawn to how big it is and how it looks in terms of sparkle-appeal (unless notable tint or pique is present). I like to prioritize education based on those things.

How often do consumers come aboard here on PS saying "I wish I had learned more about cut before I bought my diamond..." And why shouldn't they? I can take a whole box of D-FL diamonds and show you wild variations in look based on cut.

Here is an offer I make when giving presentations to trade organizations: I'll give any trade member in here a box of 12 diamonds of same carat weight and cut, ranging from D-F (GIA). I'll put up $1000 that with your naked eye you can't sort them from one another exactly as GIA did. Let's double the bet if you want to sort clarity (IF-VS) exactly as GIA did - again with your naked eye.

No one takes the bet, yet there can be >50% difference in pricing between those stones.

 

[Garry H (Cut Nut)]

I disagree Storm.
Consumers before they learn all or gem BS just care about the diamond in the ring.
If the cut can make it better or worse then why should a consumer pay for and get a different grade for what they are buying?

Date: 5/25/2009 3:42:47 PM
Author: John Pollard

Date: 5/25/2009 3:26:29 AM
Author: DiaGem
Thanks you (all) guys,

*John P..., can you elaborate a bit more on you mentioning:

''For the record, in the big (consumer) picture, I''m with Strm here.''

Any suggestions how to adapt a new grading model that will be better for consumers?

Oh gosh. Blow it up?

I mean, I love this biz but we''re wonky.

Personally, I''m riveted by differences in gemology and craftsmanship... But why do we go and force the invisible on consumers as learning and selling priorities? The first Cs you hear about in stores after carat are color and clarity. Why?? How about starting with what''s visible to any viewer: Size (simple) shape (simple) subsets of shape like 60-60 vs Near-Tolk vs Transitional vs Shallow in RB and their performance characteristics. These are visible differences even if color/clarity are the same.

Instead we have a system that divides color, clarity and finish to often-invisible levels (D Flawless can appear identical to F VS when cut the same way) and historically emphasizes these categories to consumers - yet the same system fails to differentiate notable differences in visual character (a nice 60-60 w 85% LH is different to anyone than a nice Transitional w 75% LH)...

Because pricing is driven by ''rarity'' we have made these color/clarity differences the mainstays in our lab assessments and presentations to consumers. Well I submit these are the trade''s priorities, not necessarily the consumer''s.

Size? Important! Shape? Important! Visual Character & Performance on the finger? Important! Aren''t these all priorities? And while I do think color is certainly important, in my experience a range of color may be acceptable when someone finds the size, shape and performance characteristics they like. Same with clarity.

Obviously I am in D-Z territory above. Go to fancy colors and consumer priorities logically shift.

Sorry, I know I strayed from the topic, but you asked.

John I believe Next Diamond over time will flatten out the high end of the color price curve. D might even have a larger jump than it does today, because of those who seek it out because it is #1.

But in the G to E range where very few consumers can see the difference, it is possible a more educated consumer who can actually see comparisons side by side, may simply say - "cant see the difference, give me the G".

Assuming Next Diamond is going to work - and become a global force in large diamond sales - this would be a consequence which I think is born out by some data on "stones removed from the Pricescope vendors data base" work that Leonid did some years back.
As I recall H-F and SI1 to VS2 were the hot sellers to our more informed than usual diamond junkies.

 

[diagem]

Date: 5/25/2009 3:41:47 PM
Author: Serg
Diagem,

re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?

Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?
Same answer is for Color Rarity.

Thanks what you did not ask me, who was first: chicken or egg?

Nature (Historically, the purer the rarer)..., labs and market just categorize it.

Rarity of color hue and intensity should be based on nature (just like clarity), but unfortunately is influenced heavily by labs and market.
Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says "cut to enhance optical illusion"

?

 

[diagem]

Date: 5/25/2009 4:25:27 PM
Author: John Pollard

Date: 5/25/2009 4:02:01 PM
Author: DiaGem

So you are saying the trade & labs should prioritize grades based on consumer priority? (Do I understand you correctly?)

I''m saying consumers wouldn''t start thinking ''D-K'' or ''FL-VS'' unless we as a trade taught them to do so.

A normal person doesn''t see a brand new diamond on a friend''s finger and think ''Ooh, G/H VS2/SI1...'' Normally the eye is drawn to how big it is and how it looks in terms of sparkle-appeal (unless notable tint or pique is present). I like to prioritize education based on those things.

How often do consumers come aboard here on PS saying ''I wish I had learned more about cut before I bought my diamond...'' And why shouldn''t they? I can take a whole box of D-FL diamonds and show you wild variations in look based on cut.

Here is an offer I make when giving presentations to trade organizations: I''ll give any trade member in here a box of 12 diamonds of same carat weight and cut, ranging from D-F (GIA). I''ll put up $1000 that with your naked eye you can''t sort them from one another exactly as GIA did. Let''s double the bet if you want to sort clarity (IF-VS) exactly as GIA did - again with your naked eye.

No one takes the bet, yet there can be >50% difference in pricing between those stones.

So how would you price a 1.00 ct D-IF Infinity Princess vs. a 1.00 ct F-VS1 Infinity Princess? Approx the same?

 

[John P]

Date: 5/25/2009 4:42:00 PM
Author: DiaGem

So how would you price a 1.00 ct D-IF Infinity Princess vs. a 1.00 ct F-VS1 Infinity Princess? Approx the same?

Impossible unless/until the rough material is priced the same.

But you are the one who asked me to voice my perspective - I did that. Let''s hear your solution?

 

[Serg]

Date: 5/25/2009 4:28:45 PM
Author: DiaGem

Date: 5/25/2009 3:41:47 PM

Author: Serg

Diagem,


re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?


Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?

Same answer is for Color Rarity.


Thanks what you did not ask me, who was first: chicken or egg?

Nature (Historically, the purer the rarer)..., labs and market just categorize it.


Rarity of color hue and intensity should be based on nature (just like clarity), but unfortunately is influenced heavily by labs and market.

Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says ''cut to enhance optical illusion''

?

re:but unfortunately is influenced heavily by labs and market.

Unfortunately? Are you sure? Do you prefer 30 years old prices for yellow fancy Vivid body diamonds?

re:Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says ''cut to enhance optical illusion''[

And print same(''optical illusion'' ) on Audi and BMW . these Car manufactures did not use enough rare type metals . Car Design and performance is just Optical illusion without rare and expensive metals .

What is reason to cut vivid color rough? it just reduce mass, body color is same or even worse for polished diamonds from this rough.
just sell rough to consumers

 

[diagem]

Date: 5/25/2009 4:50:21 PM
Author: John Pollard

Date: 5/25/2009 4:42:00 PM
Author: DiaGem

So how would you price a 1.00 ct D-IF Infinity Princess vs. a 1.00 ct F-VS1 Infinity Princess? Approx the same?

Impossible unless/until the rough material is priced the same.

But you are the one who asked me to voice my perspective - I did that. Let''s hear your solution?

I dont think things are that bad for consumers..., especially the ones who are willing to invest time in learning.
Consumer confidence today is better and growing...

We (the trade) need to concentrate on realistic issues that are within our control.
Education, craftsmanship, marketing ideas, transparency and most important..., integrity! (I am sure I missed a few

)

If we look for consumer over-protective ideas..., it might backlash at us (greater part of trade) and consumers...

I will keep giving my Fancy colored example..., By implementing face-up color grading, we are mass marketing low value Cape colored Diamonds as rare Fancy colored Diamonds. That is fact if you compare old (20-25+ yrs.) GIA graded Fancy colors to todays Fancy colors.

Imagine colorless Diamond grading switches to face-up grading only..., consumers will purchase H colored face-up but J colored body colors..., what will happen to base rough prices??? who will win??

 

[adamasgem]

Date: 5/25/2009 4:28:45 PM
Author: DiaGem

Date: 5/25/2009 3:41:47 PM
Author: Serg
Diagem,

re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?

Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?
Same answer is for Color Rarity.

Thanks what you did not ask me, who was first: chicken or egg?

Nature (Historically, the purer the rarer)..., labs and market just categorize it.

Rarity of color hue and intensity should be based on nature (just like clarity), but unfortunately is influenced heavily by labs and market.
Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says ''cut to enhance optical illusion''

?

More like a disclaimer "grade based on amount of bribery paid"

 

[diagem]

Date: 5/25/2009 5:08:09 PM
Author: Serg

Date: 5/25/2009 4:28:45 PM
Author: DiaGem

Date: 5/25/2009 3:41:47 PM

Author: Serg

Diagem,


re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?


Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?

Same answer is for Color Rarity.


Thanks what you did not ask me, who was first: chicken or egg?

Nature (Historically, the purer the rarer)..., labs and market just categorize it.


Rarity of color hue and intensity should be based on nature (just like clarity), but unfortunately is influenced heavily by labs and market.

Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says ''cut to enhance optical illusion''

?

re:but unfortunately is influenced heavily by labs and market.

Unfortunately? Are you sure? Do you prefer 30 years old prices for yellow fancy Vivid body diamonds?

One thing is for sure..., i prefer the Fancy Vivid cuts of 30+++ years ago vs. today''s cut to enhance optical illusion Fancy Vivids..., you cant even compare the prices they fetch at present day.

re:Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says ''cut to enhance optical illusion''[

And print same(''optical illusion'' ) on Audi and BMW . these Car manufactures did not use enough rare type metals . Car Design and performance is just Optical illusion without rare and expensive metals .

And Fancy Colored Diamonds are supposed to be rare and expensive objects or at least that is what is/was being marketed to the consumer...



What is reason to cut vivid color rough? it just reduce mass, body color is same or even worse for polished diamonds from this rough.
just sell rough to consumers

No reason..., marketing rough set designer jewelry is a segment which is growing nicely..., I sometimes prefer the natural rough shape over generic polished... (but thats just my personal taste.)

 

[adamasgem]

Date: 5/25/2009 5:20:03 PM
Author: DiaGem
I dont think things are that bad for consumers..., especially the ones who are willing to invest time in learning.
Consumer confidence today is better and growing...

We (the trade) need to concentrate on realistic issues that are within our control.
Education, craftsmanship, marketing ideas, transparency and most important..., integrity! (I am sure I missed a few

)

If we look for consumer over-protective ideas..., it might backlash at us (greater part of trade) and consumers...

I will keep giving my Fancy colored example..., By implementing face-up color grading, we are mass marketing low value Cape colored Diamonds as rare Fancy colored Diamonds. That is fact if you compare old (20-25+ yrs.) GIA graded Fancy colors to todays Fancy colors.

Imagine colorless Diamond grading switches to face-up grading only..., consumers will purchase H colored face-up but J colored body colors..., what will happen to base rough prices??? who will win??

The answer , my friend, is that prices will go up and he two winners willl be GIA and DeBeers (or other rough producers)

You see that already in grading fancy colored diamonds, as well as the change in fluorescence effects.
The big boys in the trade say screw the consumer.
Let's sell the best paper we can get, look at GIA did with their "taste test" to scientific data and "cut" grade.
People (weasels) that should be in prison, are not (yet!). Coverup after coverup.

 

[diagem]

Date: 5/25/2009 5:34:11 PM
Author: adamasgem

Date: 5/25/2009 4:28:45 PM
Author: DiaGem

Date: 5/25/2009 3:41:47 PM
Author: Serg
Diagem,

re:Serg..., who will decide Rarity and Craftsmanship on natural colored Diamond?

Who decide Rarity for inclusions grading ? Labs or market? Could you give simple answer?
Same answer is for Color Rarity.

Thanks what you did not ask me, who was first: chicken or egg?

Nature (Historically, the purer the rarer)..., labs and market just categorize it.

Rarity of color hue and intensity should be based on nature (just like clarity), but unfortunately is influenced heavily by labs and market.
Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says 'cut to enhance optical illusion'

?

More like a disclaimer 'grade based on amount of bribery paid'

with the help of our friendly cut enhancer...

Care for the J-Lo Pink anyone

.

 

[adamasgem]

Date: 5/25/2009 5:44:15 PM
Author: DiaGem

Date: 5/25/2009 5:34:11 PM
Author: adamasgem

Date: 5/25/2009 4:28:45 PM
Author: DiaGem

Nature (Historically, the purer the rarer)..., labs and market just categorize it.

Rarity of color hue and intensity should be based on nature (just like clarity), but unfortunately is influenced heavily by labs and market.
Craftsmanship info will be decided based on labs and market..., do you think GIA should add a comment to their colored report that says ''cut to enhance optical illusion''

?

More like a disclaimer ''grade based on amount of bribery paid''

with the help of our friendly cut enhancer...

Cut grade based on bad taste test...

 

[Serg]

Diagem,

re:And Fancy Colored Diamonds are supposed to be rare and expensive objects or at least that is what is/was being marketed to the consumer...

I prefer version: And Fancy Colored Diamonds are supposed to be Exclusive and expensive objects or at least that is what is/was being marketed to the consumer...

Exclusivity is not just Rarity