going to view diamonds, please advise

[jetmal]

hi,

I have 2 appts made at 2 different locations to go and look at princess cuts.

I am not obessed with finding "the" perfect diamond......I only ask that it looks large for its size (looking at 1.5-2.0), faces up white, has sparkle, and that no inclusions are visible to the naked eye.

So, which stones should I consider?? Are there any that I should positivly stay away from?

here is what I have learned from the princess cut tutorial, please correct me if I am wrong, or feel free to add anything you find helpful.

1 .) The table should be less than the depth
2 .) The depth should not be greater than 76%
3. ) A good range would be 70-ish % depth, and 65-ish% table
4.) if I can get crown and pavillion angels, thats can be helpful, crown should be at least 10% or more, and pavillion should be in the 50-60''s%

as far as color, I know that you need to rely on your eyes....but is there a suggestion as to what color I should stop considering???

thanks for all your help

 

[Garysax]

Have you considered investing in an idealscope? Fancies vary quite a bit and there are different combinations of measurements that achieve great light return--if you look at some of, say the WF expert selections or Paul''s infinity diamonds many of them don''t conform to those rules and you might end up rejecting something great. They aren''t bad rules of thumb but ultimately I would not completely disqualify things based on them if you see them in person and are impressed by their beauty.

 

[belle]

well said gary, i was going to mention the same thing.
i would absolutely not lock yourself in with those numbers jetmal, you many miss some very very nice looking diamonds.

 

[Paul-Antwerp]

I would advise you to stay away from the huge majority of stones with a depth under 73%.

On the other hand, who am I?

Live long,

 

[belle]

Date: 2/21/2006 4:24:39 PM
Author: Paul-Antwerp
I would advise you to stay away from the huge majority of stones with a depth under 73%.

On the other hand, who am I?

Live long,

who is that masked man?

 

[jetmal]

paul, so what range is good then for depth??? 73% to what?

 

[Paul-Antwerp]

Like in the analysis of rounds, one starts the analysis of a princess-cut with its pavilion. It is a point that many forget to stress.

First, you need a P2-angle, that is not too shallow, preferably over 40°. This leads to a pavilion depth of minimum 60%, and you can easily allow up to 64%.

The P1-angle may not be too deep, although with most princess-cuts, it is indeed too deep, mostly combined with a too-shallow P2.

In the crown area, you do not want a too shallow-crown. A crown-height of at least 9% is nice, if the pavilion is on the deeper side, but in most cases a crown height over 10% is a minimum.

Unlike most princess-cuts on the market, I would avoid the steeper crown angles well over 40%.

A nice table-size ranging from 60 to 70% will be the cherry on the pudding.

Total depth with a pavilion of 60%, a crown of say 11% and a girdle of 3% leads you to minimum 74%. On the other hand, 64% pavilion, 12% crown and 3% girdle is already 79%, which would be close to my maximum.

After reading all this, and trying to apply this, do not be surprised that 99% of the princess-cuts do not come close to the above measurements. Cutting for light performance in princess-cuts is very recent, and before AGS introduced their grading-system, the guidelines were only based upon choosing the best of all the bad cuts.

Live long,

 

[squarediamondlove]

I too would strongly recomend getting the ASET or the idealscope - makes the analysis much easier

Just a couple of practical points when you go in to look at diamonds. Realize that your knowlege of crown hight/angle and pavilion may not come in handy since many jewlers do not have those specs b/c they are not on the GIA report. So you may just be dealing with table and depth. Withouth the ASET or idealscope, your key measuring tool should be your eyes.

My only advice would be to:
Look and see whether the stone looks very symmetrical to you? The rating on the GIA report for symmetry doesn't count
Does the diamond look asthetically pleasing or is something not right with it (go with your gut instinct here - also is it boring or is it intersing to look at)
See how it sparkles compared to other diamonds
Once you have some experience judging princess cuts it becomes very easy to distinguish leakage in a princess cut with the naked eye. Usually the leakage areas will have a dull light gray look to it, while the areas that are properly reflecting light will look more metallic, brillian and darker when under halogen lighting.

 

[jetmal]

thank you everyone for your help. you''ve all given me great tips and advice.
I go on Thurs to one place, and Fri another.

I''ll let you know what I find!