Novice question about cut

[pregcurious]

I saw this round sapphire on Tan's site http://www.ebay.com/itm/1-32ct-CERTIFIED-Flawless-6mm-Round-Royal-Blue-Sapphire-/331005646605?pt=LH_DefaultDomain_0&hash=item4d1179570d,, but it has no video.

From the pic, I can see that the center looks "dead". Why is this? Is that a window? It's very difficult for me to tell without seeing a window, or a hand shot. The dimensions are 6.2 x 6.2 x 3.8 mm., which make me feel like the sotne may be deep enough (and therefore not have a window.)

 

[chrono]

Yes, it is a small window and the depth of the stone is 61%. Coloured stones need to be deeper cut than a diamond in order not to window due to their refractive index so 61% is just a touch shallow for a sapphire but just right for a diamond. Not only that, even if it is deep enough, there could be other reasons why the stone might show a window (working around inclusions, trying to open up the colour, etc).

 

[pregcurious]

Thanks, Chrono.

I updated my CAD thread...could you comment on the most recent changes?

 

[GregS]

I say this without seeing the video... Window or no window, that stone has nice color.

 

[chrono]

I say this without seeing the video... Window or no window, that stone has nice color.

+1. I was tempted when I first saw it a few days ago.