Is the internet, and cut grading the enemy of creativity in cutting?

[whatmeworry]

4 out of the last 5 round brilliants that I''ve bought all have P.A. = 41.2. Of course there''s leakage. No doubt. But without the ideal scope I can''t see it, even with the diamond resting on the fingers. I consider this amount of leakage minor and inconsequential. Similar to whether inclusions in a diamond are of consequence. What made these particular diamonds attractive was the high crown angles (> 35), which I love, and the price that I paid for them, which I really love.

Because I''ve bought and looked at lots of round brilliant cuts and can compare them to others, I''m comfortable with this amount of leakage. I''m not sure how a novice consumer searching for their first diamond on the internet would arrive at a comfort level for leakage (cut), inclusions (clarity), color, size without looking at a lot of diamonds in real life.

 

[Serg]

Date: 1/24/2010 10:57:21 AM
Author: Karl_K

Date: 1/24/2010 5:11:35 AM

Author: Serg


Karl,



re:Similar to what PS PRo-sumers do they no more would recommend a diamond just by the IS/ASET image than you would buy one.


NO MORE is important reference in your statement



When did it( NO MORE) happened and Why?

You read what I said wrong but that is ok I will answer.

It has never been just IS images since I have been here.

It started out as hca + is + hearts if h&a.

There never has been a one factor selection tool.

See just 3 months old example for 7.5ct P41.3Cr34.9

" Date: 10/27/2009 9:13:28 PM
Author: John Pollard
Date: 10/27/2009 8:52:24 PM

Author: Stone-cold11


As I said, the AGS stone is gamed. The stone will have leakage under table, probably used that to provide control leakage for the scintillation effect as there will be no contrast/shadow zone. The stone will definitely look less bright than other AGS0 stone. An IS/ASET image will tell more.



Actually I was surprised it made the grade, but then I saw the unique size. Wow.


The AGS cut guides predict AGS3 light performance for 57/41.3/34.9, but with something this large we''re out of the ordinary and into the extremely rare. Rules for common sizes may not apply. The 62.7%D makes me wince but if it was ray-traced and made the grade...


Still, I wish we''d had this rough. This cutter was so anxious to keep the saleable 7.5ct mark that he/she allowed extra depth in the pavilion, which takes it out of the scientific performance bullseye (and the 12.51 mm spread faces up like a 7.25ct modern Tolk in any case).


With a tiny (TINY) adjustment it could be blazing in all light conditions. Just recut the pavilion to 40.9 avg and, yes, you drop below 7.50 cts but the diamond loses NO spread, and check the difference...


41.3 Pavilion Angle, 7.55 ct



Sad, really sad.
This stone would have dark zones in the table.
Once dirty it would suffer badly.
There are better large stones around.
It was once so that 3ct H&A''s was rare. Not so any more
Garry Holloway FGAA DipDT

HCA and Ideal-scope developer"
https://www.pricescope.com/community/threads/gia-excellent-steep-deep.127766/

it is insulting, is not it?
I think what Diamond P41.3Cr34.9 have better Fire than P40.7Cr34.5(if we account Human stereo vision) and a little bit less Light return ( if we account Human stereo vision)
Of course for color-blind Cyclops the P41.3Cr34.9 could be much worse than P40.7Cr34.5

Did you inform what your advices mainly good for color-blind Cyclops???

 

[diagem]

"Is the internet, and cut grading the enemy of creativity in cutting?"

Why would you say the Internet & cut grading is the enemy of "creativity" in cutting???

Perhaps it should go like this:

"Creativity" in cutting might revolutionize the future of "cut grading" & "Internet marketing" for Gems/Diamonds...

 

[Serg]

Date: 1/24/2010 12:29:50 PM
Author: whatmeworry
4 out of the last 5 round brilliants that I''ve bought all have P.A. = 41.2. Of course there''s leakage. No doubt. But without the ideal scope I can''t see it, even with the diamond resting on the fingers. I consider this amount of leakage minor and inconsequential. Similar to whether inclusions in a diamond are of consequence. What made these particular diamonds attractive was the high crown angles (> 35), which I love, and the price that I paid for them, which I really love.


Because I''ve bought and looked at lots of round brilliant cuts and can compare them to others, I''m comfortable with this amount of leakage. I''m not sure how a novice consumer searching for their first diamond on the internet would arrive at a comfort level for leakage (cut), inclusions (clarity), color, size without looking at a lot of diamonds in real life.

Hi WMW,
thanks for information

re:What made these particular diamonds attractive was the high crown angles (> 35), which I love

Could you publish more precise Cr angle for these 4 diamonds?
Do you have IS images?

what do you love in these diamonds? why do you love high crown angles ?

 

[whatmeworry]

Date: 1/24/2010 3:53:53 PM
Author: Serg

Date: 1/24/2010 12:29:50 PM

Author: whatmeworry

4 out of the last 5 round brilliants that I''ve bought all have P.A. = 41.2. Of course there''s leakage. No doubt. But without the ideal scope I can''t see it, even with the diamond resting on the fingers. I consider this amount of leakage minor and inconsequential. Similar to whether inclusions in a diamond are of consequence. What made these particular diamonds attractive was the high crown angles (> 35), which I love, and the price that I paid for them, which I really love.



Because I''ve bought and looked at lots of round brilliant cuts and can compare them to others, I''m comfortable with this amount of leakage. I''m not sure how a novice consumer searching for their first diamond on the internet would arrive at a comfort level for leakage (cut), inclusions (clarity), color, size without looking at a lot of diamonds in real life.

Hi WMW,

thanks for information


re:What made these particular diamonds attractive was the high crown angles (> 35), which I love


Could you publish more precise Cr angle for these 4 diamonds?

Do you have IS images?


what do you love in these diamonds? why do you love high crown angles ?

I like the profile look of high crown angles. I also think that it might have better scintillation in strong spot lighting. It could be my imagination but I tried testing using a small pinhole flashight to provide the lighting. I started looking at diamonds with c.a. > 35.0 because I noticed that Tiffany & Co. started to cut a lot of their RBC with c.a. > 35.0. So I started to ask why is that? Is there something special about that? So I bought the first one, then I bought a cushion with c.a. > 40 degrees, then a couple of OEC, then more round brilliants with c.a. > 35. Let''s just say that c.a. > 35.0 by is not necessarily a detriment to me. I will post IS images and precise c.a. later today.

 

[whatmeworry]

Serg
Here are the idealscopes for some diamonds that I own that have higher crowns and/or higher pavilions than Tolkowsky. Some comments
Stone 2: Under very very dim lighting, I can start to notice very slight leakage (darkness) on the edge/girdle of the diamond in some places.
Stone 5: This is a light yellow diamond but if I could find another one like this, I would buy it because of the profile.
Stone 6: This is an average looking diamond. I would call it good. In dim lighting it is easy to see the leakage (darkness) on the edge/girdle. Also it is starting to become nail heady. I keep this around so I have an average looking diamond for comparison. It has very bad optical symmetry but under strong spot lighting the scintillation is electrical.

 

[Garry H (Cut Nut)]

Date: 1/24/2010 1:09:57 PM
Author: Serg


Sad, really sad.
This stone would have dark zones in the table.
Once dirty it would suffer badly.
There are better large stones around.
It was once so that 3ct H&A''s was rare. Not so any more
Garry Holloway FGAA DipDT

HCA and Ideal-scope developer''
https://www.pricescope.com/community/threads/gia-excellent-steep-deep.127766/

it is insulting, is not it?
I think what Diamond P41.3Cr34.9 have better Fire than P40.7Cr34.5(if we account Human stereo vision) and a little bit less Light return ( if we account Human stereo vision)
Of course for color-blind Cyclops the P41.3Cr34.9 could be much worse than P40.7Cr34.5

Did you inform what your advices mainly good for color-blind Cyclops???

Dear Sergey,
The main point that I made here is about the stone looking dirty. My experiance strongly indicates this is the case.
I have asked that you impliment some method to test this by raising the RI of the interface near the pavilion to say 1.4 (oils etc).
I have done some runs in DC pro that I will post shortly

 

[Garry H (Cut Nut)]

Date: 1/25/2010 12:08:56 AM
Author: Garry H (Cut Nut)

Date: 1/24/2010 1:09:57 PM
Author: Serg


Sad, really sad.
This stone would have dark zones in the table.
Once dirty it would suffer badly.
There are better large stones around.
It was once so that 3ct H&A''s was rare. Not so any more
Garry Holloway FGAA DipDT

HCA and Ideal-scope developer''
https://www.pricescope.com/community/threads/gia-excellent-steep-deep.127766/

it is insulting, is not it?
I think what Diamond P41.3Cr34.9 have better Fire than P40.7Cr34.5(if we account Human stereo vision) and a little bit less Light return ( if we account Human stereo vision)
Of course for color-blind Cyclops the P41.3Cr34.9 could be much worse than P40.7Cr34.5

Did you inform what your advices mainly good for color-blind Cyclops???

I have locked the Crown and table size and varied the pavilion angle (on DC default settings) from 40.7 to 41.4.
will post the legend in the next image

 

[Garry H (Cut Nut)]

Legend for the fire images

 

[Serg]

Date: 1/25/2010 12:55:08 AM
Author: Garry H (Cut Nut)

Date: 1/25/2010 12:08:56 AM

Author: Garry H (Cut Nut)

Date: 1/24/2010 1:09:57 PM

Author: Serg



Sad, really sad.

This stone would have dark zones in the table.

Once dirty it would suffer badly.

There are better large stones around.

It was once so that 3ct H&A''s was rare. Not so any more

Garry Holloway FGAA DipDT


HCA and Ideal-scope developer''

https://www.pricescope.com/community/threads/gia-excellent-steep-deep.127766/


it is insulting, is not it?

I think what Diamond P41.3Cr34.9 have better Fire than P40.7Cr34.5(if we account Human stereo vision) and a little bit less Light return ( if we account Human stereo vision)

Of course for color-blind Cyclops the P41.3Cr34.9 could be much worse than P40.7Cr34.5


Did you inform what your advices mainly good for color-blind Cyclops???

I have locked the Crown and table size and varied the pavilion angle (on DC default settings) from 40.7 to 41.4.

will post the legend in the next image

Garry,
do you remember about stereo Vision? please tilt diamond on 5 degree and compare results with Cyclops vision

 

[Garry H (Cut Nut)]

Date: 1/25/2010 1:08:05 AM
Author: Serg

Garry,
do you remember about stereo Vision? please tilt diamond on 5 degree and compare results with Cyclops vision

I have done it already - just arranging photoshop

 

[Garry H (Cut Nut)]

Date: 1/25/2010 1:08:05 AM
Author: Serg

Garry,
do you remember about stereo Vision? please tilt diamond on 5 degree and compare results with Cyclops vision

 

[Serg]

Does anybody from PS prosumers see now clear boundary between good( Tolkowsky) and bad( close to Death ring) RBC stones on this IS and Fire images?

Garry, I hope you read my last post on page4

 

[Garry H (Cut Nut)]

Data face up.
Sergey can I do mono data on 5 degree tilt?

 

[Garry H (Cut Nut)]

Date: 1/25/2010 1:37:08 AM
Author: Serg
Does anybody from PS prosumers see now clear boundary between good( Tolkowsky) and bad( close to Death ring) RBC stones on this IS and Fire images?

Garry, I hope you read my last post on page4

From page 4
Garry,

re:even with DiamCalc which does now have a fire image a little bit like an ASET image

It is not very helpful yet because we account all outgoing rays.
I want remove Pavilion rays( leakage) a soon( but may be we should not remove all pavilion rays and need account Pavilion leakage from upper hemisphere )

Yes Sergey,
I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

 

[Serg]

Date: 1/25/2010 2:09:28 AM
Author: Garry H (Cut Nut)

Date: 1/25/2010 1:37:08 AM

Author: Serg

Does anybody from PS prosumers see now clear boundary between good( Tolkowsky) and bad( close to Death ring) RBC stones on this IS and Fire images?


Garry, I hope you read my last post on page4

From page 4

Garry,

re:even with DiamCalc which does now have a fire image a little bit like an ASET image

It is not very helpful yet because we account all outgoing rays.

I want remove Pavilion rays( leakage) a soon( but may be we should not remove all pavilion rays and need account Pavilion leakage from upper hemisphere )



Yes Sergey,

I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

GArry,

re:Sergey can I do mono data on 5 degree tilt?
No

re:I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

You can easy check it now with raytracing. For my opinion this difference is minor for Cr35P41.3 in stereo vision. But for Cr35P41.7 in stereo vision and Cr35P41.2 in Cyclops vision you will see huge difference

You can name is As StereoVision Shift For RBC( In "CutGrading Maps")

 

[arjunajane]

Date: 1/24/2010 11:23:02 AM
Author: Rockdiamond


As trade members, I believe that the onus is on us to set a higher standard

Karl, now that you''re posting as a member of the trade isn''t it time to stop the insulting and pejorative tone?

David,
YOU posting as a member of the trade has not stopped you from posting in contradictory, inflammatory and argumentative ways - so I can''t help but call a clear "hyprocrite!" on the above comment.

 

[Serg]

Date: 1/25/2010 12:08:56 AM
Author: Garry H (Cut Nut)

Date: 1/24/2010 1:09:57 PM

Author: Serg



Sad, really sad.

This stone would have dark zones in the table.

Once dirty it would suffer badly.

There are better large stones around.

It was once so that 3ct H&A''s was rare. Not so any more

Garry Holloway FGAA DipDT


HCA and Ideal-scope developer''

https://www.pricescope.com/community/threads/gia-excellent-steep-deep.127766/


it is insulting, is not it?

I think what Diamond P41.3Cr34.9 have better Fire than P40.7Cr34.5(if we account Human stereo vision) and a little bit less Light return ( if we account Human stereo vision)

Of course for color-blind Cyclops the P41.3Cr34.9 could be much worse than P40.7Cr34.5


Did you inform what your advices mainly good for color-blind Cyclops???

Dear Sergey,

The main point that I made here is about the stone looking dirty. My experiance strongly indicates this is the case.

I have asked that you impliment some method to test this by raising the RI of the interface near the pavilion to say 1.4 (oils etc).

I have done some runs in DC pro that I will post shortly

re:I have asked that you impliment some method to test this by raising the RI of the interface near the pavilion to say 1.4 (oils etc).

It could give wrong and misleading results. Dirty on diamond is not Oil with RI=1.4

I advice you take shots in IS for Cr34.5P41.2 in 8 conditions
1) Clean diamond
2) Oil on Pavilion
3) after wearing this diamond 1 month
4) dirty diamond due wearing what had been clean from Pavilion only

for face up and 5 degree tilt positions

after you do it I will start work for implementation in DC
without real experiment I do not like create theory .

re:The main point that I made here is about the stone looking dirty.

I am disagree what consumer( who asked about this 7.5ct diamond) connected your FIRST statement "This stone would have dark zones in the table." with your second statement

"Once dirty it would suffer badly." Specially after John Pollard posts with IS imaged generated in DC for same diamond

 

[Serg]

Date: 1/23/2010 8:52:03 PM
Author: Karl_K

Date: 1/23/2010 1:40:28 PM

Author: Serg


re:Share your knowledge and explain your vision and educate, do not insult.



My knowledge what IS/ASET can not be used to grade Beauty of cut. For some PS persons such my statement is insult.


I publish many post in last 5 years with my explanations why ASET/IS is just rejection tools. Do many on PS happy see such explanations? I do not see so.


Main part of PS happy see support only for ASET,AGS0, etc. Other opinions do not welcome from prosumers community on PS.

We must be reading a different PS then because the pro-sumers point out that IS/ASET is for rejection all the time.

If you want them to stop using IS/ASET which has worked for years then give them something better.

Until that time they will use it along with video when they can get them.

You can not tear down what works without re-building with something better.

You will get rejected.

re:If you want them to stop using IS/ASET which has worked for years then give them something better.

I never had goal to stop using IS/ASET. It are nice and very helpful tools in skillful minds.
I ask take into account limitation these tools( and any other tools) when anybody gives advices based on these tools( specially when you penalty other diamonds)

Reflector technology has a lot limitations . it can show leakage for nice diamond , and in same time reflector technology can give perfect image even for ugly diamonds
one case when you know these limitation and take its into account in your advices and other case when you ignore these limitations and opposite opinions in aggressive style

 

[Garry H (Cut Nut)]

Date: 1/25/2010 2:36:45 AM
Author: Serg

Date: 1/25/2010 2:09:28 AM
Author: Garry H (Cut Nut)

Date: 1/25/2010 1:37:08 AM

Author: Serg

Does anybody from PS prosumers see now clear boundary between good( Tolkowsky) and bad( close to Death ring) RBC stones on this IS and Fire images?


Garry, I hope you read my last post on page4

From page 4

Garry,

re:even with DiamCalc which does now have a fire image a little bit like an ASET image

It is not very helpful yet because we account all outgoing rays.

I want remove Pavilion rays( leakage) a soon( but may be we should not remove all pavilion rays and need account Pavilion leakage from upper hemisphere )



Yes Sergey,

I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

GArry,

re:Sergey can I do mono data on 5 degree tilt?
No

re:I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

You can easy check it now with raytracing. For my opinion this difference is minor for Cr35P41.3 in stereo vision. But for Cr35P41.7 in stereo vision and Cr35P41.2 in Cyclops vision you will see huge difference

You can name is As StereoVision Shift For RBC( In ''CutGrading Maps'')

Dear Sergey,
You should remember that i have known this since August 2005
https://www.pricescope.com/community/threads/why-did-gia-included-steep-deep-diamonds-in-excellent.32135/

I have learned that leakage is not the critical issue unless it causes darkzones that are large enough to look ugly.
But I also know what I see when I look at clients dirty diamonds.

You can not believe that 57 34.9 41.3 is as good as 57 34.5 40.7 - your own system confirms it.

 

[Garry H (Cut Nut)]

Date: 1/25/2010 3:12:43 AM
Author: Serg


re:I have asked that you impliment some method to test this by raising the RI of the interface near the pavilion to say 1.4 (oils etc).

It could give wrong and misleading results. Dirty on diamond is not Oil with RI=1.4
Dear Sergey, I am sure you could devise a method to solve this issue.

I advice you take shots in IS for Cr34.5P41.2 in 8 conditions
1) Clean diamond
2) Oil on Pavilion
3) after wearing this diamond 1 month
4) dirty diamond due wearing what had been clean from Pavilion only

for face up and 5 degree tilt positions
Already about 3 years ago I set one shallow stone and one slightly deeper than Tolkowsky stone into each or Drena''s earrings and performed this test with many ordinary people and trade experts, in many lighting types. I am not sure if you saw them too? Certainly Peter Yantzer, John P and Paul S and others all prefered the shallow stone. This was a very real test because it was done by maybe 100 people from all walks of life.

There is a thread here based on it. I found this old image from April 2006 if someone wants to try to find the thread.

after you do it I will start work for implementation in DC
without real experiment I do not like create theory .

re:The main point that I made here is about the stone looking dirty.

I am disagree what consumer( who asked about this 7.5ct diamond) connected your FIRST statement ''This stone would have dark zones in the table.'' with your second statement

''Once dirty it would suffer badly.'' Specially after John Pollard posts with IS imaged generated in DC for same diamond

 

[Lorelei]

Might be this thread Garry?

https://www.pricescope.com/community/threads/hca-shallow-proportions-and-the-effects-of-dirt.26140/

 

[Serg]

Date: 1/25/2010 6:40:28 AM
Author: Garry H (Cut Nut)

Date: 1/25/2010 2:36:45 AM

Author: Serg

Date: 1/25/2010 2:09:28 AM

Author: Garry H (Cut Nut)

Date: 1/25/2010 1:37:08 AM

Author: Serg

Does anybody from PS prosumers see now clear boundary between good( Tolkowsky) and bad( close to Death ring) RBC stones on this IS and Fire images?

Garry, I hope you read my last post on page4

From page 4
Garry,

re:even with DiamCalc which does now have a fire image a little bit like an ASET image

It is not very helpful yet because we account all outgoing rays.
I want remove Pavilion rays( leakage) a soon( but may be we should not remove all pavilion rays and need account Pavilion leakage from upper hemisphere )
Yes Sergey,
I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

GArry,

re:Sergey can I do mono data on 5 degree tilt?

No


re:I can see that the fire is likely to be more where there is leakage in the tilted images, so it seems the reduced fire in 41.3 will be even further reduced when you remove the pavilion rays.

You can easy check it now with raytracing. For my opinion this difference is minor for Cr35P41.3 in stereo vision. But for Cr35P41.7 in stereo vision and Cr35P41.2 in Cyclops vision you will see huge difference
You can name is As StereoVision Shift For RBC( In 'CutGrading Maps')

Dear Sergey,

You should remember that i have known this since August 2005

https://www.pricescope.com/community/threads/why-did-gia-included-steep-deep-diamonds-in-excellent.32135/

I have learned that leakage is not the critical issue unless it causes darkzones that are large enough to look ugly.
But I also know what I see when I look at clients dirty diamonds.You can not believe that 57 34.9 41.3 is as good as 57 34.5 40.7 - your own system confirms it.

Dear Garry,
Yes, 5 last years we have long and sometimes Hot discussion about Steep Deep and Shallow diamonds.

You are disagree with my opinion, I am disagree with your opinion .

I know and I hope your remember my explanations why DC has not precise and correct model for Human stereo vision. It is very difficult to model Human brain( very complex system)

I see solid reasons why diamonds as 34.9 41.3 could create more colorful flashes in Human brain than diamonds as 34.5 40.7
you can not receive such conclusions from integrated IS images

and I saw many nice P41.2 Cr34.5 diamonds.

to solve this argument we need build Stereo LightBox( or may be Stereo Diamcalc is enough)
But in any case penalty based on ONLY IS image with minor leakage is not correct Advice.
You have rights to say "Based on my experience the table will too dark if this diamond is dirty ", But you have not any scientific support for statement as" This diamond is bad because you can easy see visible Leakage in IS"

re:Certainly Peter Yantzer, John P and Paul S and others all prefered the shallow stone.

For my TASTE shallow diamonds have Too dark zone under table. I can not understand why darkness due head obscuration is better than darkness due Leakage??
Shape of dark zones in Shallow diamonds s could looks more preferable ( Arrows instead Rind) for some persons, but it is question about TASTE

if we measure the Brightness of Shallow diamonds could be worse than Brightness of P34.5Cr41.2 diamonds for both static and dynamic observer conditions

Please separate Taste and Science in your advices

I am very interesting to hear exact Peter Yantzer Citation. what was your exact question to Peter?


re:Already about 3 years ago I set one shallow stone and one slightly deeper than Tolkowsky stone into each or Drena's earrings and performed this test with many ordinary people and trade experts, in many lighting types. I am not sure if you saw them too?

Yes, I saw it.

It is far away from my demand for such tests

 

[oldminer]

I will open a new thread with this topic: Does the way a diamond is worn, such as the difference between mounting diamonds into earrings and mounting them into rings or mounting them into pendants have enough effect on their appearance due to the way they tend to gather light from different angles mean that earring diamonds may be cut for that purpose with different angles than diamonds destined to be set into rings?

The title of the thread will be: Diamond performance- Diamond viewing position

 

[Mrs Mitchell]

I''ll be very interested in that thread, oldminer. As a wearer of diamonds, that''s the most relevant thing for me. Looking forward to it, thanks.

Jen

 

[Rockdiamond]

Yes Dave, I agree with Mrs Mitchell- I''m sure it will be interesting- however it still skirts the issues I''ve raised here.
To me, one of the most noteworthy aspects of this conversation is the apparent inability many of the other tradespeople posting have to address my simple point- which I feel is very relevant.
Instead we get hundreds of little CG images that seem only to be an attempt to obscure the issue.
Or suggestions that I personally buy rough to cut stones that would be predisposed to be knocked , based on the points I''m raising.
That is so NOT the point

If the current trend continues, there will be a totally one sided view of a diamond''s "performance"- which can certainly be a threat to diversity, and creativity.

 

[oldminer]

Because it "skirts" (your word) the issue that you are making in your thread and because it pertains to Garry and Serg''s thread hijack, I began a new topic. This in no way deletes or damages your chain of thought, but puts the argument about light behavior, DiamCalc, stereo vision, performance, etc into a thread designed to encompass that topic. I was doing your thread a favor rather than hijack it further.

I believe that the lack of creativity in cutting is due to cutters wanting or needing to cater to the vast majority of buyers who want relatively standard items. Lack of creativity caused by tight tolerances in what the mass or majority market demands. Taking huge financial risks to bring to market special cut diamonds which may fail to sell very well is not a great business choice in an economy which now scares innovation to the outer edges of business concerns. The spread of information via the Internet has caused more consumers to want similar, very well cut stones and they are skeptical of stones touted as excellent when the numbers look questionable. Sure, the numbers do not tell the whole story, but for distant buyers, the numbers give them the ability to do an excellent job over the Internet.

Innovation continues behind the scenes. Maybe a viable product will be brought to market which changes the game somewhat. I just don''t know what it is or how it will happen. We''ll all be surprised when it does occur and surely, it will happen.

 

[Rockdiamond]

My apologies Dave- I agree- the discussion was brought so far afield, a new thread made good sense.

You have been one of the pros who has addressed the question I''ve raised- although we do see it differently.
There ARE opportunities to break new ground due to the internet. Karl''s design, Horseheads- newer renditions of old mine stones- these all have gained popularity due to the internet.

The other side being the diminution of other diversity - due partly to reflector technology, and it''s easy adaptability to web advertising.

 

[Lula]

Date: 1/24/2010 12:29:50 PM
Author: whatmeworry
4 out of the last 5 round brilliants that I've bought all have P.A. = 41.2. Of course there's leakage. No doubt. But without the ideal scope I can't see it, even with the diamond resting on the fingers. I consider this amount of leakage minor and inconsequential. Similar to whether inclusions in a diamond are of consequence. What made these particular diamonds attractive was the high crown angles (> 35), which I love, and the price that I paid for them, which I really love.


Because I've bought and looked at lots of round brilliant cuts and can compare them to others, I'm comfortable with this amount of leakage. I'm not sure how a novice consumer searching for their first diamond on the internet would arrive at a comfort level for leakage (cut), inclusions (clarity), color, size without looking at a lot of diamonds in real life.

Ditto, this -- personal choice (even if it goes outside the "safe" angles) is what PS is all about! The key point, though, is in your last sentence -- how would someone know what their comfort level is if they haven't lived with/looked at a lot of diamonds in real life!

The trouble, in my experience, is that when you go to retail stores to look at diamonds in real life, you are confronted with a) lighting that is not at all real life; and, b) a selection of stones that are cut for weight not beauty. This situation puts the consumer at the mercy of not only the salesperson's skill and honesty, but also the local stores' ability or willingness to stock well-cut stones. Frankly, I assume there's more money to be made in selling poorly cut stone. Well-cut stones are rare, period. And I've noticed that vendors who do put the effort into selling well-cut stones often have statements on their websites explaining why they no longer carry non-ideal cut stones.

RD, I agree with you, the POTENTIAL for a well-cut 60-60 exists, just as I believe the POTENTIAL exists for beautiful stones with crown and pav angles outside the "safe" parameters (I learned on PS that all of a stone's facets must work together to produce a beautiful stone).

And to be clear, I am talking about rounds here.

BUT, I have not seen a well-cut 60/60 in real life in a store. My hunch is there aren't that many around because vendors can't make the profit margins on those that they can make on poorly cut stones. So they don't carry them, just like they don't carry Tolkowsky Ideal cuts. So again, it's not that creativity is being stifled, it's that vendors have no interest in carrying something that they won't make as much money on, especially when they can make $$ selling poorly cut stones to uneducated consumers.

This is an argument about cut quality, imho, more than about bias against well-cut 60-60 stones.

In fact, this week as I'm running errands, I think I will conduct a little experiment. I will visit a few local stores and ask them to show me any 60/60 RBs they have in stock. I'll take my IS scope and report back.

 

[Rockdiamond]

Sara- thanks for having an open mind- and contributing positive input!

Your hunch about the reason you don;t see a lot of "spready" well cut stones is well founded if you use a lot of what you read online as a basis.
But actually, I feel you''re proving my point.
The reason you won;t see a lot of 60/60''s is the fact they are harder to "prove" to be well cut based on internet technology.
I was talking to an amazing cutter- he improves stones to be EX cut grade, as well as cutting large quantities of EX cut grade round diamonds from the rough. He does not buy rough- but works for some major people here in NYC
I asked him which he liked better, 60/60 or 57/61 "Ideal" style.
"60/60" he answered with no hesitation.
"But the market today is all about smaller tables, Hearts and Arrows- so that''s what everyone asks for"