Does HCA matter as much as Idealscope and Aset measures?

[winstondistrict]

Could someone please give me some insights about the following stone?

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2963559.htm

My concern is that the HCA score has a "very good" for scintillation. If I remember correctly, there's not really anything that can measure the scintillation of a stone, therefore I cannot rely on the Idealscope and Aset Images? Because I can't go there and look at it in real life, I really worry that this is going to make a big difference.

I normally would really prefer a stone that has an HCA that's "ex-ex-ex-ex" or "ex-ex-ex-vg." Could someone please help me make a decision?

Any advice is sincerely appreciated.

 

[sherryd]

I think that ags ooo diamonds trump the hca result and you don't have anything to worry about.
Maybe some of the experts on the forum will chime in though to confirm this. It looks to be a
beautiful diamond

 

[krisjon]

HCA is just an elimination tool for stones that could potentially underperform based on cut proportions.

An AGS light report gauges through (ASET) the ACTUAL (not predicted) light performance. Add in IdealScope and you have two ways to see proof-positive of a stone's light performance (or lack thereof/leakage).

The stone you listed is 1.5 HCA. You're good with anything less than 2. A tenth of a degree in proportions can throw a score from EX to VG. It's probably because the pavillion angle is 40.9 instead of something slightly less. Plug in a 40.6 and it drops to a .8 and the scintillation goes to EX.

 

[treasurehunter]

ASET if I'm not wrong basically works on the same principles as HCA just its more accurate because it takes into account symmetry and other factors , HCA is free and you can do it with any cert, the two results should overlap .

 

[teobdl]

The stone you've chosen if beautiful, and probably among the best cut diamonds in the world. Literally. Scintillation is not an issue.

HCA is an experimentally and mathematically created calculator that helps you eliminate likely poor performers, and potentially predict the characteristics of light return. You input 4 measurements from a stone with 57 facets. It tells you nothing about the symmetry of the actual facets of the diamond in question, which is critical to light performance and character of the stone.

ASET and IdealScope are physical tools that help you see patterns of light return (and whether light is being returned) in the actual diamond.

Great ASET/IdealScope + HCA < 2.0 + AGS 0 = no brainer (in terms of light performance).

 

[John P]

HCA is an experimentally and mathematically created calculator that helps you eliminate likely poor performers, and potentially predict the characteristics of light return. You input 4 measurements from a stone with 57 facets. It tells you nothing about the symmetry of the actual facets of the diamond in question, which is critical to light performance and character of the stone.

ASET and IdealScope are physical tools that help you see patterns of light return (and whether light is being returned) in the actual diamond.

Well-said.

 

[winstondistrict]

Thank you all for answering my question. Your responses are definitely very reassuring!

I do have another question, is the degree of influence certain inclusions have on light performance already reflected on the Idealscope and Aset images? In other words, would the cloud under the table (in this case) affect light performance that is not shown in the report, and can only be seen in real life?

Thank you so much for your help!!

 

[Andelain]

Thank you all for answering my question. Your responses are definitely very reassuring!

I do have another question, is the degree of influence certain inclusions have on light performance already reflected on the Idealscope and Aset images? In other words, would the cloud under the table (in this case) affect light performance that is not shown in the report, and can only be seen in real life?

Thank you so much for your help!!

Not if it's an ACA. And especially not if it's a VS1 ACA! WF checks them over with a fine-toothed comb. Anything that detracts from performance eliminated them as an ACA stone. That one is a beauty!

 

[John P]

Thank you all for answering my question. Your responses are definitely very reassuring!

I do have another question, is the degree of influence certain inclusions have on light performance already reflected on the Idealscope and Aset images? In other words, would the cloud under the table (in this case) affect light performance that is not shown in the report, and can only be seen in real life?

Thank you so much for your help!!

Clouds in I and SI clarities can pose an issue, once in a while. It is more likely in a diamond where a cloud is the grade-setter, or where the comment "Clarity grade based on (clouds) not shown" appears. In my experience it's less likely with AGSL graded SI diamonds, which are graded in a single location. And, as Andelain pointed out, such outliers will already be looked-for and rejected by elite brands or other collections with good quality control.

 

[c-k]

Thank you all for answering my question. Your responses are definitely very reassuring!

I do have another question, is the degree of influence certain inclusions have on light performance already reflected on the Idealscope and Aset images? In other words, would the cloud under the table (in this case) affect light performance that is not shown in the report, and can only be seen in real life?

Thank you so much for your help!!

The other posters have addressed this question...so if I could just add this. The ASET in a AGSL report is a computer generated image which excludes any inclusions...a Idealscope is of the actual stone so inclusions could effect the image.

If you compare an Ideal cut AGSL report ASET to an Idealscope image of the same stone many times you will see they mirror each other.