Different HCA score for same diamond

[nehadp]

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

Holloway Cut Advisor | HCA Tool

The HCA Tool uses data from a round brilliant diamond to produce a score that can help you make an estimate regarding the cut quality. Use it here.

www.pricescope.com

Holloway Cut Advisor | HCA Tool

The HCA Tool uses data from a round brilliant diamond to produce a score that can help you make an estimate regarding the cut quality. Use it here.

www.pricescope.com

 

[DejaWiz]

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]

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]

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.

 

[lovedogs]

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

 

[nehadp]

The links you posted take me to the HCA tool with no data entered.

Can you post screenshots of what results you are getting?

 

[nehadp]

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

 

[Garry H (Cut Nut)]

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

Holloway Cut Advisor | HCA Tool

The HCA Tool uses data from a round brilliant diamond to produce a score that can help you make an estimate regarding the cut quality. Use it here.

www.pricescope.com

Holloway Cut Advisor | HCA Tool

The HCA Tool uses data from a round brilliant diamond to produce a score that can help you make an estimate regarding the cut quality. Use it here.

www.pricescope.com

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]

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)]

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!

 

[Karl_K]

I entered the AGS number. Below are the pics attached

h&a vs very good symmetry is the difference in the scores
The one listing hearts and arrows is correct for that stone.

 

[DejaWiz]

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]

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.

 

[Texas Leaguer]

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!

What is the report number?

 

[Garry H (Cut Nut)]

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

 

[yssie]

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

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)]

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]

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

Oh gotcha. I misunderstood. Thanks for clarifying

 

[Texas Leaguer]

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

OK, I understand. I will see what I can find out.

 

[Texas Leaguer]

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.



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

 

[Texas Leaguer]

The ASET below is the .stl rendered in DiamCalc

 

[Garry H (Cut Nut)]

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.



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]

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.