Can anyone tell me if the depth of a princess cut diamond using the measurements?

[Christy42]

Could someone please tell me the depth of this 2.09 carat princess cut with these measurements?

6.84 x 6.73 x 5.28

Also is this a good depth or a bad depth? Thanks.

 

[Rhino]

A 78.5% depth. On the deep side.

"edited to add" ... depending on the other proportions I'd rather have a princess that was a little on the deeper side (provided the other angles were complimentary) than having a princess cut with a known large table (mid to upper 70's or 80's).

Ie. If a princess cut *does* have a 78.5% depth (as is the case with this stone) but has crown angles in the 40 degree neighborhood combined with a crown height greater than 10% combined with pavilion angles (2 sets) one being around 60 degrees and the other set around 40 degrees ... (LOL... if I didn't lose you by now) you'd have a stone that while deep would have great optics.

 

[valeria101]

Date: 12/12/2004 1:59:54 AM
Author: Rhino

LOL... if I didn't lose you by now, you'd have a stone that while deep would have great optics.

Did anyone try to determine formally what is the sketchiest set of measurements that makes sense to use (=make a safe bet for visual optics) ?

From the four numbers on GIA certs to the full cut chart there is quite some distance. Where should someone concerned with casual observation stop counting ?

 

[valeria101]

Date: 12/12/2004 12:52:54 AM
Author:Christy42
Could someone please tell me the depth of this 2.09 carat princess cut with these measurements?

6.84 x 6.73 x 5.28

Also is this a good depth or a bad depth? Thanks.

Let me guess: this must have a flat face (little crown height and close to 80% table).
Otherwise I can''t get it how a stone this deep can still have reasonable spred (that 6.8-6.7 are the two diameters and determine visible size more than weight does...).

To get the same size with less extreme proporions (by AGA tables, say), a 1.7 carat princess cut around 65% deep would have at least that size. Like THIS ONE for example

 

[Cynthia]

Hi,

can you share the formula for calculating the depth when you only have the measurements?

Cindy

 

[Rhino]

Date: 12/12/2004 12:35:17 PM
Author: Cynthia
Hi,

can you share the formula for calculating the depth when you only have the measurements?

Cindy

Sure. You simply divide the depth of the diamond by the width of the stone.

This diamond has a 6.84mm length and a 6.73mm width and is 5.28mm deep.

5.28mm divided by the 6.73mm width = .7845 or 78.5% total depth.

In fancies the total depth percentage is always determined this way.

 

[RockDoc]

Date: 12/12/2004 12:52:54 AM
Author:Christy42
Could someone please tell me the depth of this 2.09 carat princess cut with these measurements?

6.84 x 6.73 x 5.28

Also is this a good depth or a bad depth? Thanks.

There is no set of numbers that will demonstrate ACCURATELY if the stone will have great light return or not.

I have seen poorly proportioned stones look great ( as well as not), and vice versa.

Basing a purchasing decisdnon primarly the numbers is not accurate and may mislead consumers.

The only number that has any consistency with light return is the crown height percentage, which should be greater than 10%

Symmetry of the faceting is a major factor in light return as is the centering of the culet ( point on bottom of stone).


There are a lot of factors in analyzing a princess or other fancy shapes,

Hope this helps.

Rockdoc

 

[Christy42]

Ok, thanks for answering, but you lost me for sure. If my calculations are correct, which they may not be, my table is about 70% and this ring has great optics. It''s size just doesn''t seem to reflect a true 2.09 carat. Being a VS2 and a color I, it seems to be a great ring except for that.

 

[Christy42]

Thank you fro responding. I calculated 77%. I guess I was close. The diamond has a color of I and is a VS2 with great optics. It just doesn''t reflect its true size because of the deep cut. I was just trying to determine where it was on the cut scale. You were a big help. Thanks again.

 

[Christy42]

Thanks for answering. I was just trying to verify my own calculations to see where this diamond landed on the cut scale. I had two different gemologists have two entirely different opinions and just wanted to see for myself. The stone is a VS2 and has color of I. It also has great optics. it''s beautiful and clean, but really doesn''t reflect its true size.