Would you be concerned about 0.7 HCA score for this diamond?

[AJJ]

I feel like I'm reading conflicting information about HCA scores < 1 and would greatly appreciate some advice.

I'm waiting to receive a diamond for an engagement ring that has a fantastic ASET image, but it has an HCA score of 0.7.

I have read multiple sources, including here at PriceScope, that HCA should only be used as a rejection tool (for scores > 2) and not for selection. I have also seen a few sources say that they would not go below 1 for rings due to performance in certain lightning conditions (e.g. under sunlight)...is this always true?

Is it possible to tell by the specs and ASET image below whether a score < 1 should be a concern? Are there any tests that I can perform once I have the diamond in my hands to confirm whether this score is a non-issue?

Thank you in advance!

• 2ct / E / VVS2
• Table: 55.9%
• Depth: 61.7%
• CA: 33.8
• PA: 40.7

 

[Karl_K]

HCA scores have evolved over time and many combos that used to be over 1 are now under 1 so the under 1 thing is not as big a deal.
With a 40.7 pavilion average under 1 is fine.
33.8 CA is just a bit shallow but the 55.9% table means it has a reasonable crown height.

 

[Karl_K]

Verify the ASET image is the right one and based on scan data.

 

[AJJ]

Verify the ASET image is the right one and based on scan data.

Thank you so much for the insight on HCA scores and the PA. After all the research that I've done, this is new info to me so this is incredibly helpful.

The image that I provided was directly from the vendor's page. Here is the one from the AGS report, which I now notice has a different graphic/visual style. It states that it's computer generated light performance.

Sorry for my ignorance, but would the fact that it comes from the report verify that it's correct?

May I also ask for your opinion on a previous option that I was comparing the stone above with? (Please see specs and image below.)

Both the vendor and some helpful PriceScope members pointed out that both options would be hard to tell apart with the naked eye, but there was some consensus on liking the slightly smaller table % and thicker arrows of the stone above. The vendor also mentioned preference for the pattern and symmetry of the option above.

Any additional thoughts would be greatly welcomed.

• 2.1ct / F / VVS2
• Table: 57.2%
• Depth: 61.2%
• CA: 34
• PA: 40.8
• HCA score: 1

 

[Karl_K]

Thank you so much for the insight on HCA scores and the PA. After all the research that I've done, this is new info to me so this is incredibly helpful.

The image that I provided was directly from the vendor's page. Here is the one from the AGS report, which I now notice has a different graphic/visual style. It states that it's computer generated light performance.

Sorry for my ignorance, but would the fact that it comes from the report verify that it's correct?

May I also ask for your opinion on a previous option that I was comparing the stone above with? (Please see specs and image below.)

Both the vendor and some helpful PriceScope members pointed out that both options would be hard to tell apart with the naked eye, but there was some consensus on liking the slightly smaller table % and thicker arrows of the stone above. The vendor also mentioned preference for the pattern and symmetry of the option above.

Any additional thoughts would be greatly welcomed.

• 2.1ct / F / VVS2
• Table: 57.2%
• Depth: 61.2%
• CA: 34
• PA: 40.8
• HCA score: 1

Lets tackle one thing at a time:
The ASET images on the report are computer generated based on scan data. Most of the time they are a reasonable approximation. Real ASET images are preferred for making a more narrow conclusion.
The other ASET you originally posted is also computer generated. They can be made 2 ways:
a: someone enters the numbers. Very inaccurate because it is just making an image based on rounded averaged then rounded numbers. In the case of gia numbers they are further grossly rounded.
b: ASET image based on scan data, with a good scan they are reasonable approximations like the ones on the report.

I do not agree with the thought that someone will prefer wider arrows. In fact some people strongly prefer one way or the other and a significant percentage probably dont care.
The table size given the different crown angles is a wash.

Bottom line is based on available information they are both well cut diamonds.
There is no evidence present here so far that they are h&a or super-ideal if they are sold as such you need to be given heart images and one of actual arrow aset or is images.

 

[AJJ]

Thank you for taking the time to make such a detailed response.

I am now noticing on the page that there is a note underneath that images are of the actual diamond, but I will confirm with the vendor just to be sure that these are real ASET images.

Yes, they were sold as such. I only have hearts images (first image below) at this time from what is listed on the page, and the computer-generated precision map (second image below) from the report. If you can extract anything from these, it would be greatly appreciated but I will definitely inquire with the vendor for further images.

Hearts image:

Computer-generated precision map from report:



Since we're also looking at the previous option, here are the same images for it:

Hearts image:

Computer-generated precision map from report:

 

[Karl_K]

hearts image looks good as do the report images.
im heading to bed and will check in when I wake up.

 

[AJJ]

Thank you and have a good night. I should head to bed too, but it's hard to quit looking into this

 

[Karl_K]

Thank you and have a good night. I should head to bed too, but it's hard to quit looking into this

lol, been there and done that.
You really can not go wrong with either one, they are both very well cut.

 

[AJJ]

lol, been there and done that.
You really can not go wrong with either one, they are both very well cut.

That is wonderful (and reassuring) to hear. Thank you very much for following up with me

 

[Wink]

For many years, I have been reading about how HCAs of less than 1 can be problematic for this, that or the other reason.

Having been the top vendor in the world for the branded diamonds I was selling, many of which had ACAs of less than 1, I can tell you with complete confidence that I think such a blanket statement is balderdash.

To properly use the tool to indicate which diamonds you wish to consider further is great. Its creator states that the tool is to be used for rejection, not for selection. He is correct.

When you have selected three to five diamonds for possible selection and have arranged with someone near you to see them, then you can make a decision properly, with YOUR EYES! Only YOUR EYES can tell you what YOU like.

I held many such viewings over the years, and I always put the diamonds on a slotted tray, in random order, and said nothing about cut, color, or clarity about any of the diamonds, only asking the viewer which diamond she/he liked most. When their eyes did the choosing, no one cared or asked what the HCA score was.

I had one client who came to Boise to see five diamonds who told me as she approached my desk, "WOW, That D color is incredible!" At my request she then went on to tell me which was the next lowest in color, correctly, of all five diamonds.

She totally gets it and always lets her eyes do the walking and the talking.

 

[Garry H (Cut Nut)]

You have had some great info already.
As the creator - a couple of comments.
1. That first stone is in my sweet spot on a sweet line slightly shallower than Tolkowsky.
2. All labs used bad viewing distances and made many mistakes as 90% of the time no one ever examines a diamond from very close up, so the shallow negative rarely applies.
3. The AGS digital images are designed for use with their digital pixel counter and do not show subtle shades - your stones are not a problem, but those images are.
4. the first image you posted is possibly a real photo but without back light - I think they are almost in the cheating camp.
5. All the AGS ASET images are taken with the blue component taking up a larger zone of obstruction that the blue represents. They use 3 modes - either too large at about 30 of the 180 degrees, much to large at about 32.5 degrees to replicate a Hearts and Arrows viewer, or ridiculously too large at 40 degrees.

 

[AJJ]

For many years, I have been reading about how HCAs of less than 1 can be problematic for this, that or the other reason.

Having been the top vendor in the world for the branded diamonds I was selling, many of which had ACAs of less than 1, I can tell you with complete confidence that I think such a blanket statement is balderdash.

To properly use the tool to indicate which diamonds you wish to consider further is great. Its creator states that the tool is to be used for rejection, not for selection. He is correct.

When you have selected three to five diamonds for possible selection and have arranged with someone near you to see them, then you can make a decision properly, with YOUR EYES! Only YOUR EYES can tell you what YOU like.

I held many such viewings over the years, and I always put the diamonds on a slotted tray, in random order, and said nothing about cut, color, or clarity about any of the diamonds, only asking the viewer which diamond she/he liked most. When their eyes did the choosing, no one cared or asked what the HCA score was.

I had one client who came to Boise to see five diamonds who told me as she approached my desk, "WOW, That D color is incredible!" At my request she then went on to tell me which was the next lowest in color, correctly, of all five diamonds.

She totally gets it and always lets her eyes do the walking and the talking.

Thank you for such a detailed response. This is so helpful. I will keep it in mind to let the "eyes do the walking about talking"!

 

[AJJ]

You have had some great info already.
As the creator - a couple of comments.
1. That first stone is in my sweet spot on a sweet line slightly shallower than Tolkowsky.
2. All labs used bad viewing distances and made many mistakes as 90% of the time no one ever examines a diamond from very close up, so the shallow negative rarely applies.
3. The AGS digital images are designed for use with their digital pixel counter and do not show subtle shades - your stones are not a problem, but those images are.
4. the first image you posted is possibly a real photo but without back light - I think they are almost in the cheating camp.
5. All the AGS ASET images are taken with the blue component taking up a larger zone of obstruction that the blue represents. They use 3 modes - either too large at about 30 of the 180 degrees, much to large at about 32.5 degrees to replicate a Hearts and Arrows viewer, or ridiculously too large at 40 degrees.

Thank you very much for this info. I feel very fortunate to receive this insight from you, the creator of the tool, on top of the great info that I have already received.