picking a princess is a royal pain

[tdiddy]

So I''ve been lurking for a while now trying to narrow down some options on a nice ~1.5 carat princess and get educated on this forum. It has been VERY helpful. I learned from PS that you can''t go on numbers alone, but generally speaking it seems as though a table % should be less than the depth. But almost everywhere I look these are impossible to find when also using the high 60''s low 70''s rule. The best I found is a 67% depth and 72% table. Why is it so difficult to meet that standard even when a stone is a very good cut (GIA)? Is a depth>table pretty much a bad bet?

 

[JulieN]

have you looked online?

 

[tdiddy]

I''ve looked at WhiteFlash, Dirt Cheap Diamonds, GOG, and Blue Nile. Budget is ~$8000.

 

[JulieN]

Minimum color and clarity?

Yes, it''s fine for a table>depth as long as I see some direct measures of light performance.

 

[tdiddy]

I would prefer H SI1 minimum

 

[JulieN]

http://www.bluenile.com/diamonds_details.asp?__fun_frm=i&pid=LD00444369&filter_id=0 A bit overbudget, large table, I think low crown, can't quite make out the numbers, and 1 for light performance.

http://www.dirtcheapdiamonds.com/diamond_detail.cfm?did=10253440 Should be in-house, so might as well ask for an Ideal Scope picture and ask if eye-clean.

http://www.exceldiamonds.com/diamond/24626.html Looks nice, but is an I color.

 

[JohnQuixote]

Hi Tdiddy. Welcome to PS. It sounds like you've done your homework. A narrow range of performance expectations can't be applied to princess cuts as they can for round stones. Fancy shapes rely more on motion and contrast effects for performance - and there is also greater opportunity for equally attractive looks using different configurations; # of chevrons, crown design, etc.

As you've learned, it's impossible to decisively predict princess cut performance based on simple proportions (though there are guidelines which help). When looking for fancies online it's best to rely on several pieces of information including human analysis from a trusted professional, whether that be a vendor, appraiser or combo thereof.

One guideline that has been helpful in development and assessment of princess cuts is the AGS light performance assessment. The lab uses computer ray-tracing and human analysis to determine the quantity and quality of light being returned to the viewer for each diamond, in motion as well as in the face-up static position. It's a 3 dimensional evaluation, where past proportions-based systems have been 2 dimensional. It's not the only system for finding a great princess but it is a nice guidepost now available - and it's leaps and bounds ahead of simple proportions or photos.

 

[Victoria]

Hi tdiddy, I am certainly no expert on princess cuts but am the proud owner of one which was purchased long before I found PS. I have found it difficult to find any concrete standards to measure a princess for quality of cut. I have included my stone''s specs for you if that will help in any way considering that my depth/table are both in the 70s. I don''t know if the experts here would consider my table/depth to be good but the stone is a sparklier as far as a princess performs and gets a lot of compliments.

1ct, E, VVS2, 5.54*5.49*4.01
depth 73%, table 75%
girdle medium/polished
culet none, sym/polish exc

 

[Paul-Antwerp]

It is correct, picking a princess is a pain. Probably, that is why European royalty is choosing more often for common folk as their brides, in stead of nobility.

Living in a kingdom, surrounded by many other kingdoms, I may have a better understanding about princesses. You must understand that they answer to different criteria than common (in the sense of non-noble) girls.

The same is true in diamonds. Where we are used to judge the ordinary (common) round brilliant with numbers, possibly topped by an Idealscope-pic, this does not help us at all in the judgment of princess-cuts. In the past, many have tried to judge princess-cuts in this same way, but in the end, we know that it does not work.

Why?

In a round-brilliant, we most often work with average numbers, which is dangerous in a way, but since the single facets rarely deviate far from that average, it gives us something to work with. Absolutely not so with princes-cuts.

In a princess-cut, it is possible to let single facets deviate very far from their average measurement, even up to 5° and possibly even more. In that way, an average angle does not help you.

It is been more than documented that depth is of no meaning in a princess-cut. Stones can have the same depth, and highly different diameters, and vice versa, up to the point of having princesses with the same diameter, and one having a depth of 65 and the other one of 75%.

There are only 4 ways that possibly work when choosing a princess-cut:

1 is to go for a stone with an AGS-report, although I must add that even within the AGS-0-grade, there are huge differences in performance, and that the 0-grade to my liking is too broad. Still, it is better than going for a GIA-graded stone, which at its best is AGS-2.

2 is to take care to get a full 3D-scan of a princess-cut, so that you can check each facet. Pay most attention to the pavilion, since that is the foundation of light performance, and if you have good angles there, and little deviation, you are off on a good start.

3 is to make sure, in combination with number 2, to get a really square stone, and to go for the utmost in symmetry combined with the good angles. If all the ingredients are good, symmetry is like the icing on the cake.

4 is to go with a trusted vendor, who knows his stuff.

Live long,