HCA vs Solasfera vs AGS0

[Diaser]

HI, I''m new here. And just wondering how HCA works?

1) I heard that Solasfera have the best light performance, but i picked a few solasfera diamonds and ran a HCA analysis, most of them didn''t score very high (greater than 2). I''m just wondering why.

2) I also want to understand how AGS0 is determined. In PS''s HCA analysis, it shows a graph outlined the AGS and GIA ideal candidates. Are ideal cut determined purely based on the table, depth, crown and pavillion information.

3) And in the HCA graph, it shows some area with the most intense orange/red color. If a diamond fall into that area, does it mean it has very good cut. If that is the case, why don''t AGS and GIA consider "only" and "all" intense organe/red color as ideal cut.

Sorry, too many questions here, but will really appreciate if you can give me some advice. I''m very confused right now ???

Thanks.

 

[whatmeworry]

Date: 1/24/2008 11:31:37 PM
Author:Diaser
HI, I''m new here. And just wondering how HCA works?

1) I heard that Solasfera have the best light performance, but i picked a few solasfera diamonds and ran a HCA analysis, most of them didn''t score very high (greater than 2). I''m just wondering why.

HCA is used for 57 facet round brilliants. Solasfera has 92 facets, so you can''t use HCA for it.

2) I also want to understand how AGS0 is determined. In PS''s HCA analysis, it shows a graph outlined the AGS and GIA ideal candidates. Are ideal cut determined purely based on the table, depth, crown and pavillion information.

AGS uses a 3D scan of the diamond and runs the scan through a proprietary ray tracing program to determine light return. Both AGS and GIA use the minor facets as well to determine the cut grade.

3) And in the HCA graph, it shows some area with the most intense orange/red color. If a diamond fall into that area, does it mean it has very good cut. If that is the case, why don''t AGS and GIA consider ''only'' and ''all'' intense organe/red color as ideal cut.


HCA, AGS, and GIA all use different methodologies to determine their cut grade. So they will agree on some and disagree on some.
Sorry, too many questions here, but will really appreciate if you can give me some advice. I''m very confused right now ???

Thanks.

 

[Garry H (Cut Nut)]

what me worry gave you excellent answers - one addition:

Date: 1/25/2008 12:32:05 AM
Author: whatmeworry

Date: 1/24/2008 11:31:37 PM
Author:Diaser
HI, I''m new here. And just wondering how HCA works?

1) I heard that Solasfera have the best light performance, but i picked a few solasfera diamonds and ran a HCA analysis, most of them didn''t score very high (greater than 2). I''m just wondering why.

HCA is used for 57 facet round brilliants. Solasfera has 92 facets, so you can''t use HCA for it.

2) I also want to understand how AGS0 is determined. In PS''s HCA analysis, it shows a graph outlined the AGS and GIA ideal candidates. Are ideal cut determined purely based on the table, depth, crown and pavillion information.

AGS uses a 3D scan of the diamond and runs the scan through a proprietary ray tracing program to determine light return. Both AGS and GIA use the minor facets as well to determine the cut grade.

3) And in the HCA graph, it shows some area with the most intense orange/red color. If a diamond fall into that area, does it mean it has very good cut. If that is the case, why don''t AGS and GIA consider ''only'' and ''all'' intense organe/red color as ideal cut.


HCA, AGS, and GIA all use different methodologies to determine their cut grade. So they will agree on some and disagree on some.
Sorry, too many questions here, but will really appreciate if you can give me some advice. I''m very confused right now ???

Thanks.

here is a simple explanation of why GIA is often a long way off HCA https://www.pricescope.com/community/threads/gia-diamond-dock-simple-summary.42538/
and here is a debate between GIA and the group I work with
http://journal.pricescope.com/Articles/50/1/Letter-to-the-Editor-of-the-Australian-Gemmologist.aspx