Numbers Experts - what do you think of this stone?

[strmrdr]

A 40.8 pavilion is near universal when cut tight.
It works with crown angles from 14.5 degrees to 35.5 degrees with tables from 40% to 63% and with lgf% from 75% to 85% with acceptable limits of obstruction and leakage.
There is a huge range of balancing fire and brightness in that range.
Changing the pavilion angle will yield better performance with some of the combos in that range but there is not likely an ugly diamond in the bunch.

That said images are still needed because not all 40.8 pavilions will be well cut.

We should really move this to another thread....

 

[Lorelei]

Date: 7/14/2009 5:43:27 PM
Author: strmrdr
A 40.8 pavilion is near universal when cut tight.
It works with crown angles from 14.5 degrees to 35.5 degrees with tables from 40% to 63% and with lgf% from 75% to 85% with acceptable limits of obstruction and leakage.
There is a huge range of balancing fire and brightness in that range but not likely an ugly diamond in the bunch.

Well said.

 

[Lorelei]

Date: 7/14/2009 5:43:27 PM
Author: strmrdr
A 40.8 pavilion is near universal when cut tight.
It works with crown angles from 14.5 degrees to 35.5 degrees with tables from 40% to 63% and with lgf% from 75% to 85% with acceptable limits of obstruction and leakage.
There is a huge range of balancing fire and brightness in that range.
Changing the pavilion angle will yield better performance with some of the combos in that range but there is not likely an ugly diamond in the bunch.

That said images are still needed because not all 40.8 pavilions will be well cut.

We should really move this to another thread....

Good idea, do you want to start one?

Sorry for the threadjack Jill, just trying to get a few pertinent points cleared up here.

 

[djm111]

Just for my own personal situation and while we are on the topic, would my stone suffer from any major obstruction issues?

Here are the stats:

GIA Cert
1.249 Round Brilliant
Diameter: (6.89-6.92) 6.91
Table Size: 58.9
Crown Angle: 33.94
Pavilion Angle: 40.67
Star Length: 58.4
Lower Halves: 72.9
Girdle Minimum: 1.82
Girdle Maximum: 2.68
Culet: none
Crown Height: 13.67
Pavilion Depth 42.82
Total Depth: 60.8

Thanks All.

 

[strmrdr]

djm111:
Not excessive as far as percentage of the time it shows but with Lower Halves of 72.9 it will be larger than some when it does show.

 

[jill_s]

Didn't realize that my post would cause such commotion! I really appreciate everyone's input. The stone in question is an SI2, so I'm now trying to decide if I like the clarity plot...it looks rather messy.

 

[Rhino]

I understand Stone's concern. I'd certainly want to compare the 2 side by side before plunking down the green.

Jill ... clarity plots are both a blessing and a curse.

They're good for identification but terrible in showing actual contrast of the inclusions ... ie. how easily or faint they appear under magnification and to the eye.