Princess Cut - Cut Advice

[jdunn37]

Hello all.. I am in the market for a Princess cut to put into an e-ring. I am having a little trouble determining what is a good cut for a Princess.

I see some conflicting info on various web sites and forums. For example:

A guide on this site states these parameters are ideal:

Table% 62-68
Depth% 64-75
CrownHeight% 10-15

BlueNile lists these parameters as it''s Signature Ideal:

Table% 65-72
Depth% 63-70
CrownHeight% 8.5-13.5


They are pretty similar but, BlueNile seems to go higher on Table% and lower on CrownHeight and Depth.

Anybody have an good advice or personal thoughts/experiences for a newbie?

Thanks!

 

[JohnQuixote]

Hi jdunn.

Your first set looks like it's from Dave Atlas' GemAppraisers site.

There is no lab doing "Ideal" grading yet, although AGS will be soon. Here is a recent article written by a highly regarded cutter (Paul Slegers). It is a great perspective on what is "out there" and possible future trends.

Personally, I believe the Dave Atlas parameters you found to be quite good. Be sure you bring back specifics (and especially images of a prin) to post and you will get plenty of feedback from consumers here.

 

[Paul-Antwerp]

The problem with these guidelines is that they are based on the summarized Sarin-information. Unfortunately, this does not include any info on the two crown angles, and on the highly critical first pavilion-angle.

AGS'' research has shown that one needs at least that info in order to assess the cut.

Also, these guidelines (like AGA) are based on the currently available princess-cuts. When AGS launches its cut-grading system, we will see some proportion-combinations, that are not on the market now, and which clearly outperform the best of the current best. Since these combos were not considered when establishing these guidelines (like AGA), they will fall outside of these ideal guidelines. Basically, AGS has us thinking outside of the box, and we need to be aware that that old box might be old hat by now.

If you are seriously in the market for a princess-cut, and if cut and light performance is truly important to you, I would wait a few months until the first AGS-0-princess cuts are available. You can then still decide what you choose, the new 21st-century model, or the older one.

Live long,

 

[valeria101]

Date: 1/27/2005 4:9:44 AM
Author: Paul-Antwerp

if cut and light performance is truly important to you, I would wait a few months until the first AGS-0-princess cuts are available.

Are these candidates for AGS0 ?

 

[Paul-Antwerp]

Date: 1/27/2005 4:36:39 AM
Author: valeria101

Date: 1/27/2005 4:9:44 AM
Author: Paul-Antwerp

if cut and light performance is truly important to you, I would wait a few months until the first AGS-0-princess cuts are available.

Are these candidates for AGS0 ?

Impossible to say.

Live long,

 

[diagem]

My personal opinion is that a beautifull princess cut should have a table % below 70%.

The depth is subject to your preferd taste, Ive seen princesses with a t.d. of over 75% that were beautifull, but you pay extra for the weight that accumulates in the girdle. (which is a waste of MONEY) especialy when you pay for a jump in size diamond!!!!

Make sure you purchase a stone with a relative thin girdle....

but again i think a diamond no matter what shape should include a small table to be considered a good speciment (50% to 69% depending on the shape)

And yes there are some gorgeous diamonds out there with 50 % tables!!!!

 

[jdunn37]

Thanks for the advice thus far... It''s a little frustrating to be doing my shopping right on the eve of a new standard being unveiled. It really throws a wrench into things...

I am currently considering this stone that I found online... By today''s "standard" this stone looks like a pretty good cut, am I wrong?

Report: GIA
Carat: 1.02
Color: D
Clarity: VS1
Measurements: 5.54-5.60-3.96
Depth: 71.50%
Table: 69%
Culet: N
Polish: EXCELLENT
Symm: EXCELLENT

Girdle: (2.9% - 3.8%)
Crown: 10.3%
Pavillion: 58%


Any thoughts on this one?

Now, If I could only get my girl to decide what kind of setting she likes best... sheesh....

 

[oldminer]

"The problem with these guidelines is that they are based on the summarized Sarin-information. Unfortunately, this does not include any info on the two crown angles, and on the highly critical first pavilion-angle.
AGS' research has shown that one needs at least that info in order to assess the cut. "
xxxxxxxxxxxxxx

Paul: I know your intentions are good, but one does not have to have a Sarin to "measure" crown angles or pavilion angles to "assess" the cut if one uses a better tool. If you have a tool that directly measures Light performance, then the measurement of angles, beyond a durability point, is pretty much a dead horse. The AGS proposal is like calculating the weight of a diamond from its dimensions when a scale is close at hand. Simply using the scale is the way we all would prefer to go. The "better tool" is making its way to the trade in the coming weeks....

The AGA Cut Class of old is going to be superseded by technology and a greatly revised AGA strategy. The grading of cut will either be predictive and/or directly measured. I'm in the camp that says, "use the scale--measure directly". Most people are presently looking at the big powers of the business who have huge vested interests or expenses in the predictive model.

I would "predict" that directly measuring performance will be much more exact and elegant than predictive models. Prediction is a good tool for cutters and stone designers but far less useful for accurately describing individual cut stones. There are so many unmeasured parts of diamonds that 3D modeling and/or ray/beam tracing can't adequately predict the outcome.