Using HCA on GIA Ex/Ex to get idea of AGS 0 likelihood - possible or no?

[angeline]

If a stone I am looking at has only a GIA report ( WF Expert Selection) then if I use the HCA and it falls within the outline on the graph for AGS 0, is it safe to assume it is of a cut comparable to an AGS 0? GIA gave it Ex/Ex for symmety and polish. Hope my question makes sense!

Thank you all,

a

 

[jasontb]

I would assume that if WF sent an ES to GIA it is not an AGS 0. I could be wrong, though. Let''s just say it''s a guess until you get some wiser responses.

 

[Rhino]

I wouldn't rely on the HCA alone to determine if the stone would make AGS "0" grade as there is more to determining the AGS 0 grade than just a basic set of proportions as used by the HCA. If you give the folks at WF a call and speak to John, Bob or Brian I'm sure they are familiar with what features go into determing whether it would make ideal grade regarding facet measurements for ideal.

Kind regards,

 

[Regular Guy]

Date: 8/30/2006 2:42:04 AM
Author: jasontb
I would assume that if WF sent an ES to GIA it is not an AGS 0. I could be wrong, though. Let's just say it's a guess until you get some wiser responses.

Though I think the variation we should be talking about is between reports (DQR vs DQD) and not graders (AGS vs GIA), the net effect is the same, and has come up recently, a good bit.

A main question...if it can be answered, rather than speculated about...is it:

a) mostly the chicken...or the egg
b) a mix of one first, the other second
c) none of your business

 

[belle]

only diamonds actually graded by ags and given the '0' grade can be considered ags0. anything else is a 'candidate' for ags0. you can be assured however, if you have a diamond that falls within ags0 parameters, that it will be a top performer. some might even say...comparable.

 

[Rod]

Date: 8/30/2006 10:11:40 AM
Author: belle
only diamonds actually graded by ags and given the ''0'' grade can be considered ags0. anything else is a ''candidate'' for ags0. you can be assured however, if you have a diamond that falls within ags0 parameters, that it will be a top performer. some might even say...comparable.

As usual, a terrific response from Belle!

Ira.......you crack me up

 

[Lorelei]

Date: 8/30/2006 10:20:35 AM
Author: Rod

Date: 8/30/2006 10:11:40 AM
Author: belle
only diamonds actually graded by ags and given the ''0'' grade can be considered ags0. anything else is a ''candidate'' for ags0. you can be assured however, if you have a diamond that falls within ags0 parameters, that it will be a top performer. some might even say...comparable.

As usual, a terrific response from Belle!

Ira.......you crack me up

I know Rod - isn''t she the greatest??

 

[Regular Guy]

Date: 8/30/2006 10:20:35 AM
Author: Rod

Ira.......you crack me up

Well, hopefully the humor doesn''t confuse the question, asked another way...

Which comes first:

a) determination an expert selection does not merit ACA, or
b) determination by AGS it does not get three zeros.

 

[angeline]

Hi all,

Thanks for all your responses. Belle was spot on with what I was asking.

All I wanted to kow really was whether it was at least a candidate for AGS0 i.e. had the right numbers on paper. I know there are other parameters that are required to be looked at before it can be an AGS0. I just wondered if the numbers were within their params. I guess I icould just go look up what AGS use as their cut numbers...

a

 

[RockDoc]

Date: 8/30/2006 10:48:41 AM
Author: angeline
Hi all,

Thanks for all your responses. Belle was spot on with what I was asking.

All I wanted to kow really was whether it was at least a candidate for AGS0 i.e. had the right numbers on paper. I know there are other parameters that are required to be looked at before it can be an AGS0. I just wondered if the numbers were within their params. I guess I icould just go look up what AGS use as their cut numbers...

a

Short of sending the stone to AGS you could get an AGS member who has the PGS software to image the stone and come up with an result of the AGS cut grade.

The stone has to be seen and scanned to accomplish this..... although with the .srn or .stl files a "risky" attempt at it can be made. I say risky because the polish symmetry standards of AGS are far more stringent than GIA''s, and even if the proportions are right, the "slightest" polishing mark or meet point details of the symmetry instantly "dings" the cut grade.

Rockdoc

 

[aljdewey]

Date: 8/30/2006 1:46:19 AM
Author:angeline
If a stone I am looking at has only a GIA report ( WF Expert Selection) then if I use the HCA and it falls within the outline on the graph for AGS 0, is it safe to assume it is of a cut comparable to an AGS 0? GIA gave it Ex/Ex for symmety and polish. Hope my question makes sense!

Thank you all,

a

Well, ES stones usually have more than just a grading report - they usually also have Sarin information. If it has Sarin information, then I think the HCA can still be useful to you.

If it truly has only a GIA report, as you say, then the HCA is less useful because the numbers on the GIA report are rounded. Since the rounded data may skew the HCA score, the HCA score is less useful when using only numbers from a GIA report.