Help! Depth % Question...

[Leprechaun]

Hi there everyone. Thanks to all of you on this site who provide so much useful knowledge to rookies like myself.

I have a quick question about a round brilliant stone at which I''ve been looking. Its total depth % is listed at 63.6% on the GIA report accompanying it. I know that falls outside of the ideal range but I''m wondering how much of a potential problem that is.

Besides that one possible drawback the stone is exactly what I''m looking for and I''ve compared it side by side with an AGS0 and couldn''t tell any difference in brilliance or fire.

Would appreciate any advice! Thanks.

 

[quaeritur]

If the stone is this deep because the girdle is thick, it probably won't affect the performance, as long as the other parameters are good. If the depth comes from a combination of steep crown and pavilion angles, it might leak light under the table. In either case, you might be paying for weight you cannot see, because it's in the depth rather than the spread, so you'll get a smaller diameter than you would on a more ideal cut stone.

Also, not all AGS0 stones are the best performers, so it's hard to say if this stone would look as good as a top notch AGS0 or fantastic H&A cut.

Having said all that, you should also trust your eyes. Make sure the stone looks good in different lighting conditions (not just under the lights in a jewelry store), and if it speaks to you, you have your answer!

 

[Garry H (Cut Nut)]

A diamond with a small table, shallow pavilion and steep crown angles can have 64% depth and still be nice. But they are fewer and harder to find.

 

[valeria101]

that depth can have two unpleasant effects on how the stone looks: - #1 it could indicate undesirable proportions all the way hence less brilliance than desired, and #2 could make the stone look smaller(have a smaller diameter) than other of the same weight but less depth.

Of course, neither of these could hapen and the respective percentage be a non issue. To sort these out, a few more details are needed:

- for #1: table percentage, crown and pavilion angles or percentages, and the symmetry grade.

- for #2: the dimeter!

The angles would come from a Sarin report. The diameter is already on the diamonds cert, no matter what type it is.

As a side note... it does matter where this extra depth is - a thick girdle would "hide" quite a bit more volume (and weight) than the tip of th culet!

 

[quaeritur]

Ah yes, the ever-elusive FIC!!! I hope to someday finally see one in person!

 

[Garry H (Cut Nut)]

Q, have you seen the pic on the Front page of IS?

 

[yowahking]

as someone said, get a sarin report on the diamond. It is cheap and the seller should gladly get it done. Not everydealer has one, but they all know someone who does. It will give you a better picture of how well it is cut. If you can't tell the difference to a zero cut than ok, but don't pay for a zero cut when yours could be a 2 and worth 18% less. The big downside to GIA certs. Not enough info on cut.
Scott

 

[Garry H (Cut Nut)]

Scott that stone on the front page of Is is probaly AGS 2.
Worth less, but more beautiful. Some people do not buy diamonds for "worth"

 

[oldminer]

I agree that, under certain conditions, a deeply cut diamond can be a beauty. Look at the classic Asscher cut for an example of how depth combined with proper cutting techniques can produce an excellent result....




HOWEVER, overly deep always results in less diameter. No one can argue this point and I think it is a strong issue to keep in mind. The apparent size of a diamond is only transmitted to other viewers by diameter, not depth. To me, it is a major cutting fault when a diamond is deeper than others of similar shape, outline, that perform as well or better with light. The ultimately best diamonds are highly brilliant, scintillating and show their size, too.




Combining color, clarity, cut quality, shape, weight, and light behavior is a very complicated process. It was tough enough with the 4C's, but there is so much more to doing the best possible job. It also is very clear to most experts that only a few people can see the slight falling off in light performance from the best stones to the next group right below them. You have to learn what is changed or missing. It is not highly visible, but when we speak about top quality, it can be defined. Stones not quite at the top will look very good, but then it becomes a matter of your choice. In diamonds, some people will say that if I can't see it, it doesn't matter. Others will say, I may not be able to see it, but I could never live knowing something was not quite right....To each their own.

 

[Leprechaun]

Thanks so much everyone for the helpful responses! A little more info:

The table % is 56, the symmetry rating is very good, the girdle is medium, and the diameter is 7.04x7.10x4.50 (the diamond is 1.38 carats). Does this give any more indication on the cut quality?

I'll certainly get a sarin report done as well.

 

[oldminer]

Still all in the plus column