AGS-0 falls just outside HCA''s AGS range?

[mepp]

Hi all!

Long time lurker finally making a post. I''m looking at a .807 RB diamond with the following specs:

This is taken from an AGS Diamond Quality Document:

Measurements: 5.97 - 6.00 x 3.69
Cut Grade: AGS Ideal 0
Color: G
Clarity: VS2
Fluro: Negligible

Polish: Ideal
Symmetry: Ideal
Table: 54.4%
Crown angle: 34.3
Crown height: 15.6%
Girdle: faceted, 1.3% to 4.3%
Pavilion angle: 40.6
Pavilion depth: 42.7%
Star length: 53%
Lower girdle length: 76%
Total depth: 61.6%
Culet: Pointed

When I plug the relevant values into HCA, it gets a nice score (though somewhat closer to the older people''s range than the younger range. But, it sits just outside the AGS-0 range, despite that it''s an AGS-0. Is this expected?

Thanks!

 

[mepp]

Here''s the HCA result:

 

[Regular Guy]

I think the AGS0 platinum is only generally tied to the specific markers for crown & pavilion tolerances that Garry documents in the HCA. Based on the broad range of minor facets and how they contribute to the total make-up of the diamonds, and its expected light performance, mapped 3D style, that diamond should be considered as good probably as any other 0. But I think others will be able to confirm. I don''t think you should need to feel an option should be double checked twice...first by the HCA, and then by the outline. The zero earned is designed to be a tighter fit than both of those.

 

[Garry H (Cut Nut)]

Date: 7/3/2009 11:14:41 PM
Author: Regular Guy
I think the AGS0 platinum is only generally tied to the specific markers for crown & pavilion tolerances that Garry documents in the HCA. Based on the broad range of minor facets and how they contribute to the total make-up of the diamonds, and its expected light performance, mapped 3D style, that diamond should be considered as good probably as any other 0. But I think others will be able to confirm. I don''t think you should need to feel an option should be double checked twice...first by the HCA, and then by the outline. The zero earned is designed to be a tighter fit than both of those.

In addition, that range is the range given as safe to manufacturers - and if the stone has all the good bits working together, then there have been examples achieve the software determination based on the 3D scan of zero light performance as per AGS software.
Note too that the data i saw toothed zig zag - and the x is inside a ''zag''

 

[mepp]

Date: 7/4/2009 12:30:42 AM
Author: Garry H (Cut Nut)

In addition, that range is the range given as safe to manufacturers - and if the stone has all the good bits working together, then there have been examples achieve the software determination based on the 3D scan of zero light performance as per AGS software.

Note too that the data i saw toothed zig zag - and the x is inside a ''zag''

Thanks for the helpful replies! I hadn''t at all thought about how you display the AGS range using discrete rather than continuous values, and this diamond is definitely inside a zag

I should also say, thanks so much for providing such an enormous wealth of information! PS, HCA, the ideal scope, etc., have given me such an education over the past 1-2 months -- and I feel extremely fortunate for it.

 

[Todd Gray]

The diamond definitely falls within the AGS Ideal 0 proportions range on the charts issued by the AGS Laboratory for the measurements you''ve indicated...

 

[Garry H (Cut Nut)]

Date: 7/4/2009 2:27:18 AM
Author: Todd Gray
The diamond definitely falls within the AGS Ideal 0 proportions range on the charts issued by the AGS Laboratory for the measurements you''ve indicated...

Which charts Todd - the manufacturers guide for Platinum light performance based, or the Gold system?