Why does this radiant perform so poorly?

[jeffcwang]

Hello,

I'm trying to find a Radiant Cut diamond and it's been really difficult to find a good performing radiant with no inclusions. The closest I've come is a G S1 from GoG but it had an eye-visible inclusion right in the center. I've been looking at B2C and they seem to have really high quality stones (based on the 4 C's) but the ASETs perform poorly. Why is that? Here's an example:

http://www.b2cjewels.com/dd-4983262-2.03-carat-Radiant-diamond-E-color-VVS1-Clarity.aspx?sku=4983262&utm_source=pricescope.com&utm_medium=referral&utm_campaign=pricescope.com

The ASET shows that there is tons of light leakage but it has an "excellent" polish & symmetry and the table/depth seem to fit into the proper ranges. Can anyone educate me on why this wouldn't perform well?

Thanks

 

[kenny]

The ASET shows that there is tons of light leakage but it has an "excellent" polish & symmetry and the table/depth seem to fit into the proper ranges. Can anyone educate me on why this wouldn't perform well?

Polish and Symmetry do not determine light performance.
Light performance is determined by the proportion recipe, which involves things like depth and table percentages, crown and pavilion angles.

Symmetry is how closely, precisely, and symmetrically the cutter followed the cut recipe when placing the facets.
Polish grades the surface quality of the facets.

A diamond with poor light performance can get Excellent polish and symmetry grades because the cutter did a superb job following a recipe intended to save weight instead of a recipe to achieve good light performance.

Likewise, a skilled chef can precisely follow a recipe for food that tastes mediocre and has low nutrition when the recipe's purpose is to feed 100 people as cheaply as possible.

The girdle may have been placed to high (too close to the table) or low (too close to the culet) because that gave them the heaviest diamond from the shape of the rough stone this radiant was polished from.
This would be revealed by strange crown and pavilion angles.
Unfortunately the GIA report does not reveal the crown and pavilion angles and this vendor did not provide a side view pic.

The ASET shows lots of leakage so I'd pass.

 

[MelisendeDiamonds]

Hello,

I'm trying to find a Radiant Cut diamond and it's been really difficult to find a good performing radiant with no inclusions. The closest I've come is a G S1 from GoG but it had an eye-visible inclusion right in the center. I've been looking at B2C and they seem to have really high quality stones (based on the 4 C's) but the ASETs perform poorly. Why is that? Here's an example:

http://www.b2cjewels.com/dd-4983262-2.03-carat-Radiant-diamond-E-color-VVS1-Clarity.aspx?sku=4983262&utm_source=pricescope.com&utm_medium=referral&utm_campaign=pricescope.com

The ASET shows that there is tons of light leakage but it has an "excellent" polish & symmetry and the table/depth seem to fit into the proper ranges. Can anyone educate me on why this wouldn't perform well?

Thanks

I am not going to comment on the diamond itself but I must say that ASET image itself is of such poor quality and seems to be generated(fraught with error) rather than photographed.

I should also point out that if you want a rectangular radiant you shouldn't be expecting performance like a round.

 

[smitcompton]

Hi Jeff,

There is a radiant diamond on B2jewels that Gypsy mentioned yesterday, I think, and I have been trying not to buy it. I am not computer literate so I will describe the item. It is 2.01, or 2.02 carats and has three Gia excellents. Best of all, to me, its a Fl. diamond, is I in color, and is 13,400.00 . It has an aset that Gypsy said looks very good(She would buy it, and on her say so, so would I.).
I wish I could pull the trigger, but who better than a nice young man who wants a beautiful diamond. I hope you read this soon.


Wishing you the best.

Annette

 

[jeffcwang]

Thanks for the responses. I do understand that rectangulars will not perform as well as squares.

@smitcompton: I looked for the stone you described and I think it's this one: http://www.b2cjewels.com/dd-5307487-2.01-carat-Radiant-diamond-I-color-IF-clarity.aspx

It looks beautiful but unfortunately, my girlfriend likes the rectangular ones...