Puzzling diamond numbers... what to make of them?

[Dreamer_D]

So this diamond is an AGS0, but scores poorly on the HCA. Based on the information below, how would this diamond perform?

crown < : 34.8
Pavilion <: 41.2
table: 58.4%
depth: 61.6%
star: 54 (?)
lgf: 83

I have not seen a combo like this before.

 

[Lorelei]

Date: 4/9/2010 1:55:45 PM
Author:dreamer_d
So this diamond is an AGS0, but scores poorly on the HCA. Based on the information below, how would this diamond perform?

crown < : 34.8
Pavilion <: 41.2
table: 58.4%
depth: 61.6%
star: 54 (?)
lgf: 83

I have not seen a combo like this before.

This happens sometimes Dreamer, the angles are hovering around steep deep range which account for the HCA score, and the HCA penalizes for steeper pavilion angles, however the longer LGF's can help to offset leakage so it could be helpful in this case to get the stone the AGS0 cut grade, but as you know IS are the best way of judging how effective any range of proportions are.

 

[stone-cold11]

ditto. could work but I would like to see a real IS image of it.

 

[Dreamer_D]

Date: 4/9/2010 2:00:23 PM
Author: Lorelei

Date: 4/9/2010 1:55:45 PM
Author:dreamer_d
So this diamond is an AGS0, but scores poorly on the HCA. Based on the information below, how would this diamond perform?

crown < : 34.8
Pavilion <: 41.2
table: 58.4%
depth: 61.6%
star: 54 (?)
lgf: 83

I have not seen a combo like this before.

This happens sometimes Dreamer, the angles are hovering around steep deep range which account for the HCA score, and the HCA penalizes for steeper pavilion angles, however the longer LGF''s can help to offset leakage so it could be helpful in this case to get the stone the AGS0 cut grade, but as you know IS are the best way of judging how effective any range of proportions are.

This is what I was wondering about, because I noted that the lgf was particularly long!

I am not considering this one, it just popped up and I looked around and it made me wonder.

 

[Lorelei]

Date: 4/9/2010 2:11:58 PM
Author: dreamer_d

Date: 4/9/2010 2:00:23 PM
Author: Lorelei

Date: 4/9/2010 1:55:45 PM
Author:dreamer_d
So this diamond is an AGS0, but scores poorly on the HCA. Based on the information below, how would this diamond perform?

crown < : 34.8
Pavilion <: 41.2
table: 58.4%
depth: 61.6%
star: 54 (?)
lgf: 83

I have not seen a combo like this before.

This happens sometimes Dreamer, the angles are hovering around steep deep range which account for the HCA score, and the HCA penalizes for steeper pavilion angles, however the longer LGF''s can help to offset leakage so it could be helpful in this case to get the stone the AGS0 cut grade, but as you know IS are the best way of judging how effective any range of proportions are.

This is what I was wondering about, because I noted that the lgf was particularly long!

I am not considering this one, it just popped up and I looked around and it made me wonder.

I was a wee bit curious whether you had a special reason for asking....

 

[Dreamer_D]

Date: 4/9/2010 2:14:16 PM
Author: Lorelei

Date: 4/9/2010 2:11:58 PM
Author: dreamer_d

Date: 4/9/2010 2:00:23 PM
Author: Lorelei

Date: 4/9/2010 1:55:45 PM
Author:dreamer_d
So this diamond is an AGS0, but scores poorly on the HCA. Based on the information below, how would this diamond perform?

crown < : 34.8
Pavilion <: 41.2
table: 58.4%
depth: 61.6%
star: 54 (?)
lgf: 83

I have not seen a combo like this before.

This happens sometimes Dreamer, the angles are hovering around steep deep range which account for the HCA score, and the HCA penalizes for steeper pavilion angles, however the longer LGF''s can help to offset leakage so it could be helpful in this case to get the stone the AGS0 cut grade, but as you know IS are the best way of judging how effective any range of proportions are.

This is what I was wondering about, because I noted that the lgf was particularly long!

I am not considering this one, it just popped up and I looked around and it made me wonder.

I was a wee bit curious whether you had a special reason for asking....

Not for this one, but I have made a decision finally about what I am going to do, so hopefully big news before too long

 

[susimoo]

Can we have a hint, please?

 

[Lurchie]

Date: 4/9/2010 2:41:38 PM
Author: susimoo
Can we have a hint, please?

Pretty please? I am not good at holding my breath!

 

[Karl_K]

I see a few people have been paying attention :}
It is a good questions.
optical symmetry would also help this diamond get the ags0 score.

Here is the answer in more detail:
http://journal.pricescope.com/Articles/68/1/Do-the-pavilion-mains-drive-light-return-in-the-modern-round-brilliant.aspx

 

[Dreamer_D]

Interesting article Storm. So in this particular stone, the cutter lengthened the lgfs to help minimize the leakage that would otherwise have resulted from the steep PA. I could not see an IS of this particular diamond, but the photo was not so great. I would like to see such a diamond in person to know if the compensation of the lgfs can actually completely offset the steep PS compared to a more ideal angle combo.

Had jon even made a vid of this phenomenon to your knowledge? I don''t mean the longer lgfs in a diamond with optimal CA/PA angles, but rather the longer lgfs with a steep PA.

 

[Dreamer_D]

Date: 4/9/2010 2:44:56 PM
Author: Lurchie

Date: 4/9/2010 2:41:38 PM
Author: susimoo
Can we have a hint, please?

Pretty please? I am not good at holding my breath!

You will have to wait and see

 

[Lula]

Date: 4/9/2010 4:27:03 PM
Author: Karl_K
I see a few people have been paying attention :}

It is a good questions.

optical symmetry would also help this diamond get the ags0 score.


Here is the answer in more detail:

http://journal.pricescope.com/Articles/68/1/Do-the-pavilion-mains-drive-light-return-in-the-modern-round-brilliant.aspx

The very article that turned me into a cut fanatic

Read at your own risk

newbies!

Karl, the long lgf''s would reduce leakage, but would also produce a diamond with "splinterly" fire and flash, right? Or would the higher crown angle mediate that effect?

 

[Lula]

Date: 4/9/2010 4:48:55 PM
Author: dreamer_d

Date: 4/9/2010 2:44:56 PM

Author: Lurchie

Date: 4/9/2010 2:41:38 PM

Author: susimoo

Can we have a hint, please?

Pretty please? I am not good at holding my breath!

You will have to wait and see

About how long would you say we have to wait? Can you tell us that much at least?

 

[Karl_K]

Date: 4/9/2010 4:54:57 PM
Author: sarap333

Date: 4/9/2010 4:27:03 PM

Karl, the long lgf''s would reduce leakage, but would also produce a diamond with ''splinterly'' fire and flash, right? Or would the higher crown angle mediate that effect?

Somewhat in the center of the stone, other virtual facets are increased in size so not as much as you would think.

 

[Dreamer_D]

Date: 4/9/2010 4:56:01 PM
Author: sarap333

Date: 4/9/2010 4:48:55 PM
Author: dreamer_d

Date: 4/9/2010 2:44:56 PM

Author: Lurchie

Date: 4/9/2010 2:41:38 PM

Author: susimoo

Can we have a hint, please?

Pretty please? I am not good at holding my breath!

You will have to wait and see

About how long would you say we have to wait? Can you tell us that much at least?

haha... I am not trying to be coy, I just don''t like seeming like such a wishy washy always posting different ideas and then changing my mind. I am about 99% sure this time I will not change my mind. But I don''t have an eta. Will depend how long it takes to find exactly what I want and have it set. I think a few months at least. So best to just go about your business

 

[Karl_K]

Date: 4/9/2010 5:52:53 PM
Author: Karl_K

Date: 4/9/2010 4:54:57 PM

Author: sarap333

Date: 4/9/2010 4:27:03 PM


Karl, the long lgf's would reduce leakage, but would also produce a diamond with 'splinterly' fire and flash, right? Or would the higher crown angle mediate that effect?

Somewhat in the center of the stone, other virtual facets are increased in size so not as much as you would think.

video
http://www.vimeo.com/4095697

Ignore the first part because we know that it is the lower half angle that controls leakage the mains control the degree of obstruction.

 

[Lula]

Date: 4/9/2010 5:56:29 PM
Author: Karl_K

Date: 4/9/2010 5:52:53 PM

Author: Karl_K

Date: 4/9/2010 4:54:57 PM


Author: sarap333

Date: 4/9/2010 4:27:03 PM



Karl, the long lgf's would reduce leakage, but would also produce a diamond with 'splinterly' fire and flash, right? Or would the higher crown angle mediate that effect?

Somewhat in the center of the stone, other virtual facets are increased in size so not as much as you would think.

video

http://www.vimeo.com/4095697


Ignore the first part because we know that it is the lower half angle that controls leakage the mains control the degree of obstruction.

Great video, thanks! That link would be a good one for "Helpful threads" if it's not there already. A great visual demonstration of how much the lgfs influence the personality of an H&A ideal cut stone, and nice the Rhino/Jon included the well-cut OECs for comparison on appearance.

 

[Lula]

Date: 4/9/2010 5:53:32 PM
Author: dreamer_d

Date: 4/9/2010 4:56:01 PM

Author: sarap333

Date: 4/9/2010 4:48:55 PM

Author: dreamer_d

Date: 4/9/2010 2:44:56 PM


Author: Lurchie

Date: 4/9/2010 2:41:38 PM


Author: susimoo


Can we have a hint, please?

Pretty please? I am not good at holding my breath!

You will have to wait and see

About how long would you say we have to wait? Can you tell us that much at least?

haha... I am not trying to be coy, I just don''t like seeming like such a wishy washy always posting different ideas and then changing my mind. I am about 99% sure this time I will not change my mind. But I don''t have an eta. Will depend how long it takes to find exactly what I want and have it set. I think a few months at least. So best to just go about your business

Well, that''s good news that you''ve made a decision and are just waiting to find the perfect stone(s). But I will miss reading about your ideas -- very interesting with good feedback from everyone, and, even more important, it kept me from obsessing about the stones I''m stalking on Wink''s site!

 

[Dreamer_D]

Date: 4/9/2010 6:16:22 PM
Author: sarap333


Well, that''s good news that you''ve made a decision and are just waiting to find the perfect stone(s). But I will miss reading about your ideas -- very interesting with good feedback from everyone, and, even more important, it kept me from obsessing about the stones I''m stalking on Wink''s site!

Well, you can always try to track down the diamond that I posted about and then you will know what I am waiting for

LOL! Ya know, if you have nothing better to do

 

[Lula]

Date: 4/9/2010 6:55:42 PM
Author: dreamer_d

Date: 4/9/2010 6:16:22 PM

Author: sarap333



Well, that''s good news that you''ve made a decision and are just waiting to find the perfect stone(s). But I will miss reading about your ideas -- very interesting with good feedback from everyone, and, even more important, it kept me from obsessing about the stones I''m stalking on Wink''s site!

Well, you can always try to track down the diamond that I posted about and then you will know what I am waiting for

LOL! Ya know, if you have nothing better to do

Game on! I love a good mystery!

 

[Dreamer_D]

Date: 4/9/2010 7:47:44 PM
Author: sarap333

Date: 4/9/2010 6:55:42 PM
Author: dreamer_d

Date: 4/9/2010 6:16:22 PM

Author: sarap333



Well, that''s good news that you''ve made a decision and are just waiting to find the perfect stone(s). But I will miss reading about your ideas -- very interesting with good feedback from everyone, and, even more important, it kept me from obsessing about the stones I''m stalking on Wink''s site!

Well, you can always try to track down the diamond that I posted about and then you will know what I am waiting for

LOL! Ya know, if you have nothing better to do

Game on! I love a good mystery!

I don''t think it will be that hard

 

[risingsun]

Date: 4/9/2010 7:57:48 PM
Author: dreamer_d

Date: 4/9/2010 7:47:44 PM
Author: sarap333

Date: 4/9/2010 6:55:42 PM
Author: dreamer_d

Date: 4/9/2010 6:16:22 PM

Author: sarap333



Well, that''s good news that you''ve made a decision and are just waiting to find the perfect stone(s). But I will miss reading about your ideas -- very interesting with good feedback from everyone, and, even more important, it kept me from obsessing about the stones I''m stalking on Wink''s site!

Well, you can always try to track down the diamond that I posted about and then you will know what I am waiting for

LOL! Ya know, if you have nothing better to do

Game on! I love a good mystery!

I don''t think it will be that hard

But your business is our business, dreamer

When you are sure about the diamond, couldn''t you give us a little linky

 

[Lorelei]

Date: 4/10/2010 12:39:34 AM
Author: risingsun

Date: 4/9/2010 7:57:48 PM
Author: dreamer_d

Date: 4/9/2010 7:47:44 PM
Author: sarap333

Date: 4/9/2010 6:55:42 PM
Author: dreamer_d

Date: 4/9/2010 6:16:22 PM

Author: sarap333



Well, that''s good news that you''ve made a decision and are just waiting to find the perfect stone(s). But I will miss reading about your ideas -- very interesting with good feedback from everyone, and, even more important, it kept me from obsessing about the stones I''m stalking on Wink''s site!

Well, you can always try to track down the diamond that I posted about and then you will know what I am waiting for

LOL! Ya know, if you have nothing better to do

Game on! I love a good mystery!

I don''t think it will be that hard

But your business is our business, dreamer

When you are sure about the diamond, couldn''t you give us a little linky

T''is. So there.

 

[Lurchie]

Date: 4/9/2010 4:48:55 PM
Author: dreamer_d

Date: 4/9/2010 2:44:56 PM
Author: Lurchie

Date: 4/9/2010 2:41:38 PM
Author: susimoo
Can we have a hint, please?

Pretty please? I am not good at holding my breath!

You will have to wait and see

As if! Where''s the emotie for a Bronx cheer?

[Exhales...for now]