WF ACA HCA score of 0.7, will it be dark?

[theshirlgirlNS]

I’ve just selected an ACA diamond that I thought would be perfect for an engagement ring upgrade, but have noticed on the HCA tool that it mentions a 0.7 may appear dark up close - and is more suitable for pendants/jewelry. thoughts on this?

Diamond | 2.882 ct J SI1 A CUT ABOVE® Hearts and Arrows Super Ideal Round Cut Loose Diamond AGS Certified | 4161791

This Whiteflash A CUT ABOVE® super ideal cut hearts and arrows 2.882 carat J color SI1 clarity loose diamond is graded by the American Gem Society (AGS) Laboratories. | 4161791

www.whiteflash.com

 

[lovedogs]

Nope, won't be dark at all. The HCA tool is not necessary for branded super ideal cuts or for AGS000, and this is both. It's the most helpful for GIAXXX, since GIA isn't very strict on cut, so the HCA helps you know if angles are working together or not.

Your stone will be gorgeous!

 

[sledge]

Simply put, the HCA takes select data from the lab report and makes a "best guess" to performance.

The stone in question has good proportions, but more importantly it has advanced images that prove its a real performer.

The actual advanced data trumps the best guess produced by the HCA.

 

[daisygrl]

I was once interested in the stone from Whiteflash ACA line - it scored 1.4 on HCA but only two out of four were "excellent." I could not get that out of my mind so I did not purchase it. ACA is known for a super ideal cut but this one did not feel like it was. Even in person it did not feel like it.

 

[Texas Leaguer]

I was once interested in the stone from Whiteflash ACA line - it scored 1.4 on HCA but only two out of four were "excellent." I could not get that out of my mind so I did not purchase it. ACA is known for a super ideal cut but this one did not feel like it was. Even in person it did not feel like it.

Hi @daisygrl,
Just a word about interpreting the results from the HCA tool. As others have posted above, the HCA tool is very limited in the information it processes. The outputs should not be considered definitive in any way. As anyone who has participated here for very long has learned, the HCA tool serves basically to weed out table/crown/pavilion measurements that would likely result in performance problems. Garry Holloway, the inventor of the tool, makes this clear in the following caveats:

“The Holloway Cut Adviser is a rejection tool to help you narrow your search for only round diamonds potential Light Return, Fire, Scintillation and Spread based (only) on the proportion information from a grading report. HCA does not use symmetry, polish and minor facets info.”

The ‘minor’ facets comprise 40 of the 57 facets! This is why Garry also clearly advises to validate HCA results with Ideal Scope and ASET.

The HCA tool is most useful in vetting GIA diamonds, especially those with no advanced performance images available. It is essentially of zero value in understanding AGS diamonds with light performance based reports, and can in fact be very misleading.

The AGS system does MUCH more than just plug a few rounded and averaged facet measurements into a table of predetermined outputs. The AGS system actually ray traces the light interacting with ALL of the facets calculating the impacts of 30,000 virtual light rays and testing for brightness, leakage, contrast and fire. Any significant deficits in any of these areas will result in a grade demotion from 0. So a triple zero has passed through this sophisticated system with no deductions.

Therefore, if you are looking at an AGS Triple Zero, especially a precision cut diamond with outstanding optical symmetry (H&A), it is highly counterproductive to try to reconcile the HCA guestimates for brilliance, fire, and scintillation with the actual ray traced results from the AGS system.

The HCA tool has been written about extensively on the forum by John Pollard and other experts, and many threads are searchable here for more insights on its relevance and best use.

 

[Texas Leaguer]

I’ve just selected an ACA diamond that I thought would be perfect for an engagement ring upgrade, but have noticed on the HCA tool that it mentions a 0.7 may appear dark up close - and is more suitable for pendants/jewelry. thoughts on this?

Diamond | 2.882 ct J SI1 A CUT ABOVE® Hearts and Arrows Super Ideal Round Cut Loose Diamond AGS Certified | 4161791

This Whiteflash A CUT ABOVE® super ideal cut hearts and arrows 2.882 carat J color SI1 clarity loose diamond is graded by the American Gem Society (AGS) Laboratories. | 4161791

www.whiteflash.com

Hi @theshirlgirlNS,
You might find the comments about the HCA tool that I just posted above to daisygrl to be instructive.

But more to your specific question about obstruction it should be noted that the AGS light performance system analyzes contrast by ray tracing the diamond at both 30 and 40 degrees of obscuration (head shadow), so at close and at very close observation. It also analyzes contrast and the other light performance factors through 15 degrees of tilt, as opposed to simple face up view.

So you can be fully confident that an AGS triple zero will perform well as both a ring and a pendant.

 

[Karl_K]

The latest update to the hca added some bonus factors that make more combinations score under 1 than before.
40.7 pavilion its going to be fine.

 

[theshirlgirlNS]

@Texas Leaguer thank you so much for the detailed response. I really appreciate it. In the end I chose a slightly larger diamond (https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-4135230.htm). It too has some proportions that are slightly outside of some of the online charts that show "super ideal" proportions, but I trust that there's more to the combination of angles that what can easily interpreted from paper.

Would love any thoughts you have on the diamond I did end up going with!

 

[Texas Leaguer]

@Texas Leaguer thank you so much for the detailed response. I really appreciate it. In the end I chose a slightly larger diamond (https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-4135230.htm). It too has some proportions that are slightly outside of some of the online charts that show "super ideal" proportions, but I trust that there's more to the combination of angles that what can easily interpreted from paper.

Would love any thoughts you have on the diamond I did end up going with!

@theshirlgirlNS ,
If I comment on a Whiteflash diamond I would likely violate one of the forum rules for posting by a trades person which is recommending a diamond! The posts above were made to address questions about the HCA tool and the relevance of those scores to the evaluation of an AGS Triple 0 with advanced images.

Having said that, your Whiteflash consultant can put you in touch with me if you have any questions that she is not able to answer, or if you just want a second opinion.

 

[theshirlgirlNS]

oops, my bad - sorry, should've realized!

 

[diamondseeker2006]

We normally do not use the HCA with superideal diamonds because they are all graded by ags and have additional evidence of the light return with ASET images, etc.

 

[sledge]

Woah @theshirlgirlNS....3.24 J IF!!!

Nothing to be concerned about with that stone. It's an ACA and is going to be a little (ummm....BIG) sparkle bomb!

Guessing you were worried about the table. 54-57 is frequently recommended but ACA allows up to 58. Not a big deal. Everything is cut to excellence for maximum beauty.

 

[Texas Leaguer]

oops, my bad - sorry, should've realized!

No worries. It's a common occurrence but the trades people here are really good about respecting that rule.
Of course, if they don't the moderators are diligent about posting reminders

 

[theshirlgirlNS]

Woah @theshirlgirlNS....3.24 J IF!!!

Nothing to be concerned about with that stone. It's an ACA and is going to be a little (ummm....BIG) sparkle bomb!

Guessing you were worried about the table. 54-57 is frequently recommended but ACA allows up to 58. Not a big deal. Everything is cut to excellence for maximum beauty.

Thank you so much!!! It was the table that threw me a little off, but I was still feeling pretty confident based on the many useful comments here. I like the term "sparkle bomb" - that's definitely what I'm going for. Here's hoping for the best!

 

[sledge]

Of course, if they don't the moderators are diligent about posting reminders

First offense:

Second offense:

Third offense:

 

[Garry H (Cut Nut)]

Hey it me, the H in HCA - these are about my favorite proportions. You will love it!

 

[lovedogs]

We normally do not use the HCA with superideal diamonds because they are all graded by ags and have additional evidence of the light return with ASET images, etc.

This. HCA is not needed for super ideal or AGS 000.