princess cuts

[poorsucker]

Ok, this stuff is really difficult. I read Fred Ceullar''s book and he suggests no greater than 65% table and 65% depth for square cuts. The AGA chart recommends up to 72% table and 75% depth for up to class 1b princesses. Everything gets much more strict if I want a radiant....

So I am confused. I cant find diamonds meeting Fred''s definition of GIA class II anywhere. I am looking for something in a 4-5K price range and was hoping to get somewhere near a carat in a square stone. Is this impossible? I am not naive enough to think that this is a good investment, but I shudder at the fact of flushing all this money down the drain. Another article on this site states that it may not be possible to find decent square stones on the internet. Can someone shed some light on the subject? Thanks,

Marc

 

[valeria101]

Date: 2/21/2005 11:34:40 PM
Author:poorsucker


So I am confused. I cant find diamonds meeting Fred's definition of GIA class II anywhere.[...] Can someone shed some light on the subject?

"Shed light" makes a good pun... since all this is about comes down to optics, really.

It surely is better to see diamonds in person, but then... what to do without knowing what to look for ? The stats and numbers and tests talked about on this forum and presentatble online tell you what to look for. It just so happens the same reasons amount to some premium.

Joke aside, I am not sure if it is easier to compare diamonds in flesh or by numbers without experience with either. Fred does advice in favor of sellers with large inventories who could present dozens of diamonds to choose from. But... let's face it: does this ever happen ? And even that dozen diamonds will definitely not teach what the choices are unless you know what to look for - again. Tell me where I go wrong

Several rules of thumb about table and depth go around... without much explanation for what they mean. It took some reading between the lines to come up to some conclusion. Perhaps it may help you. If not (given I am no expert) please ask - the author of the AGA charts (David Atlas, aca. "OldMiner") posts on Pricescope. Here goes:

I would thik those numbers are just good to tell three things: if the stone is somehow more fragile than it should, if it's large enough for it's weight and if it sparkles. Size for weight is easier to tell because the diameter gives size. perhaps the 65% or 70% or whatever limit of preffered depth is meant to guarantee size for weight - however, thick girdles eat up more material than a couple % of extra depth. That remains outside the rule of thumb. The limit on table size might have something to do with durability (80% table almost certainly eats up all crown height and exposes the princess edges to chipping, I've been told). What table & depth have to do with brilliance, no idea. Obviously a whole range of optics is feasible for any table & depth combination. The crown height of the AGA charts mproves the situation, but no one cared to evaluate just how much.

The stone you have selected passes all checks by numbers described above. It just remains to be seen !

On the other hand, you might find princess cuts selected for brilliance listed by specialized sellers. If deeper these might not be as large for the weight and there's some premium for the better optics. Without comparable stats for the one you found it is hard (for me at least) to guess what looks to expect from those numbers.

Hope some of this makes sense

 

[poorsucker]

Thanks