Question on Princess Cut Numbers

[PermaGrin]

First off, a big thank you for this forum and the many members who help! I can''t begin to tell you how much I have learned from following the threads of others. Thanks to all!

Now to my question. I am trying to find that "ideal" diamond that will steal my girlfriends breath away. I am looking for a Princess Cut and I am trying to best determine a diamond from "numbers" on a website. Yes, it would be ideal to be able to see it first, but in this day of virtual shopping, I am doing my best by looking at reports and specs on the diamond. I have learned that an ideal Princess Cut conforms to the following: (please correct me if I am wrong)

Crown: 8% to 14%
Shape: 1 to 1.02
Depth: 63 to 70%
Table: 65 to 72%
Polish/Sym: Exc to Very Good

{then there are the many things I am unsure of that I was hoping for some help on....}
From a Sarin Report:
?? Crown Angle Percent?
?? Pavillion Angle % ?
?? Pavillion Height ?
?? Girdle Thickness?

Question : I have looked at an IdealScope image of a potential Princess Cut and it has a small bright white X in the dead center of the table. I think this represents "light leakage", yes? Is that okay and the fact that it is right in the middle okay? How does that affect its look (and I know look is very general - aka scintillation, fire, etc)?

Question : When shopping for a diamond on-line, I can ask for a Sarin and IdealScope report, but if they don''t have either, can I have them send it somewhere to get one (at my cost)?

I am so glad I accidentally came across PriceScope and this forum. I am sure with what I have learned here along with your help, I am going to knock her socks off

Thanks!

PS I am sure more questions will follow

 

[Rhino]

Hi Permagrin (cool name btw)

In answer to your questions ...

Now to my question. I am trying to find that ''ideal'' diamond that will steal my girlfriends breath away. I am looking for a Princess Cut and I am trying to best determine a diamond from ''numbers'' on a website. Yes, it would be ideal to be able to see it first, but in this day of virtual shopping, I am doing my best by looking at reports and specs on the diamond. I have learned that an ideal Princess Cut conforms to the following: (please correct me if I am wrong)

Crown: 8% to 14%
Shape: 1 to 1.02
Depth: 63 to 70%
Table: 65 to 72%
Polish/Sym: Exc to Very Good

Good information to have but certainly not conclusive. Not by any means.

{then there are the many things I am unsure of that I was hoping for some help on....}
From a Sarin Report:
?? Crown Angle Percent?
?? Pavillion Angle % ?
?? Pavillion Height ?
?? Girdle Thickness?

Garnering this info is way more helpful but ... still not conclusive. You see ... (and I''ve been saying this even before AGS came out with their new guidelines) there is more than one set of crown angles and more than one set of pavilion angles that must be attained to begin to give an idea of optical performance of a princess cut. As it is with rounds there are may combinations that *work* in a princess cut but there are seemingly more that do not work. There are tools on hte market to help the Gman (or layman for that matter) pick the best and unfortunately most companies can not provide *all* the numberes that an educated gemologist can assess for optimal brilliiance.

Question : I have looked at an IdealScope image of a potential Princess Cut and it has a small bright white X in the dead center of the table. I think this represents ''light leakage'', yes? Is that okay and the fact that it is right in the middle okay? How does that affect its look (and I know look is very general - aka scintillation, fire, etc)?

A. Yes it is leakage.
B. That small amount of leakage is common in princess cuts.
C. As long as it is minimal it will not affect the overall brilliance, fire or scintillation. In IS/LS/FS images it''s nice to see a balance of some blacks and dark reds in there OR Bscope results in the high to very high range.

Question : When shopping for a diamond on-line, I can ask for a Sarin and IdealScope report, but if they don''t have either, can I have them send it somewhere to get one (at my cost)?

Yes. RockDoc has both a FireScope and a BrillianceScope. Rich Sherwood has the IdealScope & DiamCalc. Dave Atlas has the IdealScope and Imagem. Each of these appraisers are top notch and can give you the assessment you''re looking for.

I am so glad I accidentally came across PriceScope and this forum. I am sure with what I have learned here along with your help, I am going to knock her socks off

Thanks!

PS I am sure more questions will follow

We''ll do what we can to help.

Peace,

 

[Rhino]

For an FYI here are the 2 sets of angles to be attained in order to get an idea where the stone will fall. The first set of crown/pavilion angles are in red, the second in blue.

 

[oldminer]

We will be ready to process Princess cuts and Marquise shaped diamonds with ImaGem for Cut and Light Behavior grading starting Monday, 4/4. The final tweaks have been done for round diamond grading as well.

Within a very short time we''ll also be offering full ImaGem grading documents with computerized color grading, highly accurate measurements and automated clarity plotting . We are turning blue from holding our breath while the slow roll out happens. Technology is cool, but it takes tons of patience.

I have been a long time proponent of numbers to screen potential diamonds, but have always said your eyes are needed to make a real choice. Even with results from ImaGem, your own eyes are still of great importance in this process.