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Different HCA score for same diamond

nehadp

Rough_Rock
Joined
Jun 16, 2021
Messages
23
Hi,
I am looking at a diamond and thought to use price scope HCA calculator.
It's showing different HCA scores. I tried it multiple times.
Below are the diamond and different scores. Does price scope has predetermined scores? Or is this tool broken?
diamond : https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-4149994.htm
 

DejaWiz

Brilliant_Rock
Joined
Apr 23, 2021
Messages
904
The links you posted take me to the HCA tool with no data entered.

Can you post screenshots of what results you are getting?
 

Karl_K

Super_Ideal_Rock
Trade
Joined
Aug 4, 2008
Messages
11,712
did you enter the report # or the information yourself?
Selecting h&a or different values for lab symmetry grade will change the hca score all else the same.
 

DejaWiz

Brilliant_Rock
Joined
Apr 23, 2021
Messages
904
did you enter the report # or the information yourself?
Selecting h&a or different values for lab symmetry grade will change the hca score all else the same.

This is a great point.
Being a WF ACA, the H&A option should always be selected.
 

nehadp

Rough_Rock
Joined
Jun 16, 2021
Messages
23
did you enter the report # or the information yourself?
Selecting h&a or different values for lab symmetry grade will change the hca score all else the same.

I entered the AGS number. Below are the pics attached 200276272_134303455459261_7756548629375756707_n.jpg 198178999_1146735909139604_7372417829751088654_n.jpg
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
16,716
Hi,
I am looking at a diamond and thought to use price scope HCA calculator.
It's showing different HCA scores. I tried it multiple times.
Below are the diamond and different scores. Does price scope has predetermined scores? Or is this tool broken?
diamond : https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-4149994.htm

Please paste screen captures. It is likely to do with the symmetry grade that you entered. The system is digital and can not vary.
 

lovedogs

Super_Ideal_Rock
Premium
Joined
Jul 31, 2014
Messages
14,103
Please paste screen captures. It is likely to do with the symmetry grade that you entered. The system is digital and can not vary.

I expect it was the symmetry rating you entered and because you didn't mark that it was an H&A stone on one of them
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
16,716
ALso you don't need to use the HCA for AGS diamonds because they already have "ray tracing" on the reports, and AGS 000 is much stricter than GIA XXX

Last week I found a diamond on a dealers site that had an AGS O score listed and it was a real (not lovely) dog. I asked if anyone had AGS PGS software to check its .stl file. No one seems to have it or there is a conspiracy not to check it!
1624319377776.png
 

DejaWiz

Brilliant_Rock
Joined
Apr 23, 2021
Messages
904
h&a vs very good symmetry is the difference in the scores
The one listing hearts and arrows is correct for that stone.


Nailed it. The 1.1 score is the correct one.

@nehadp this diamond is an outstanding choice!
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,465
As Garry (the inventor of the HCA - Holloway Cut Advisor) makes clear, his tool is designed to be used as a 'rejection' system rather than a 'selection' system. He emphasizes the importance of having light performance imagery such as Ideal Scope and ASET to make a final selection.

When a diamond already has all that - has been through the AGS ray tracer as Ideal, AND you have available IdealScope and ASET imaging to verify minimal leakage and high facet precision - the HCA score is moot.
 
Last edited:

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,465
Last week I found a diamond on a dealers site that had an AGS O score listed and it was a real (not lovely) dog. I asked if anyone had AGS PGS software to check its .stl file. No one seems to have it or there is a conspiracy not to check it!
1624319377776.png

What is the report number?
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
16,716
What is the report number?
It has not been to AGS Brian, a vendor uses PGS software and promoted the diamond as receiving AGS PGS score of zero.
I have attached the .stl file 8-)
 

Attachments

  • AGS bad HCA.stl
    56.7 KB · Views: 8

yssie

Super_Ideal_Rock
Premium
Joined
Aug 14, 2009
Messages
23,052
It has not been to AGS Brian, a vendor uses PGS software and promoted the diamond as receiving AGS PGS score of zero.
I have attached the .stl file 8-)
That sounds all sorts of shady. Sounds like they’re counting on the reader not picking up on the PGS differentiation. I hope it’s not a vendor commonly recommended here on PS.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
16,716
That sounds all sorts of shady. Sounds like they’re counting on the reader not picking up on the PGS differentiation. I hope it’s not a vendor commonly recommended here on PS.

This is a trade company not a retailer Yssie. They are not shady.
 

yssie

Super_Ideal_Rock
Premium
Joined
Aug 14, 2009
Messages
23,052

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,465
Garry,
I ran it by the folks in the lab and the .stl file you attached does not correlate to the ASET you posted. Perhaps the vendor got his data wrong.

Below is the ASET of the .stl attached to your post. The diamond received a light performance grade of 2, but close to the borderline of 1.

1624473399389.png

The ASET you posted is a diamond that would grade 5 or lower, according to the lab.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
16,716
Garry,
I ran it by the folks in the lab and the .stl file you attached does not correlate to the ASET you posted. Perhaps the vendor got his data wrong.

Below is the ASET of the .stl attached to your post. The diamond received a light performance grade of 2, but close to the borderline of 1.

1624473399389.png

The ASET you posted is a diamond that would grade 5 or lower, according to the lab.

Thankyou so very much Bryan! It clearly was a mistaken keystroke by an operator.

I have just checked around 50 stones on that companies website that are listed as having AGS 0 PGS scores and none look like that one I posted.
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,465
Glad to be able to help Garry.

This situation illustrates another weakness of the virtual inventory model and one of the things shoppers should keep in mind when evaluating diamonds that the merchant does not have direct access to. Even those listings that do have a light performance image attached to them require a certain faith that the representation is accurate.

In-stock diamonds presented with a full set of evaluations that cross-validate one another give a shopper a much higher degree of confidence in the actual quality of the diamond.
 
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