Help deciding between stones and question about HCA Test

[HShelby]

Hello all-

I am brand new to the forum world, but excited for some additional input from you all!

I have recently begun my diamond search and have now spent countless hours researching and narrowing down what I believe I am looking for. I currently have two stones on hold at James Allen:

http://www.jamesallen.com/loose-diamonds/round-cut/1.75-carat-h-color-vs1-clarity-excellent-cut-sku-525657

http://www.jamesallen.com/loose-diamonds/round-cut/1.81-carat-h-color-vs2-clarity-excellent-cut-sku-470362

I came across the HCA test a few days ago and was a little confused by the findings. The 1.75 stone to me appears more sparkly in the video, however it scored low on the HCA test at 6.1. The 1.81 stone scored nicely at a 2.1 even though it does have a bit of a shallow crown angle at 32 degrees. Am I not seeing things correctly, or does the 1.75 not appear brighter and more fiery? The 1.75 is $400 less than the 1.8, not a big deal at all. I know that ultimately the actual physical look to my eye is the most important thing, but regardless, I am still confused why the one which actually appears more sparkly is scoring low on the HCA. Is this one of the instances where the HCA is more favorable to the shallower angled stone? And is the 1.75 not a good choice because it is scoring low even though it looks clear, bright and sparkly? Unfortunately not stones are not available for idealscope imaging.

Any help would be much appreciated! Thanks!

 

[ivany]

For starters, the videos differ in lighting conditions from one stone to the next. From what I understand, the videos vary between stones because they are shot by different vendors, at different times. I would guess that they don't keep the lighting setups identical.

 

[HShelby]

Yeah I did consider this to possibly be part of the reason, but even so, there is such a big difference in score on the HCA, I'm just wondering if someone can explain how accurate or reasonable that test is. Its just seems like its telling me a stone that appears incredibly sparkly is not a good choice. I know the video can't compare to viewing the stone in person, I wish that was possible!

 

[ivany]

Why don't you spend some time and take a look at a few stones in person? Walk into a store and compare two stones side by side. See if you notice a difference between the amount of "sparkle" a stone with a score of ~2 has in comparison to a stone with an HCA >3. There are a bunch of great videos on youtube from good old gold that will give you a good idea of what to look for. Take a look at "Tiffany Diamond vs GOG Hearts and Arrows Diamond."

If you were to have the ability to compare the two stones you chose side by side, you would quickly realize that the 2.1 has more life to it.

1.75 ct and 1.81 are so close to one another in terms of size that you should consider them identical. The price difference of $400 is negligible to you, so consider their price identical as well. You're left with one stone that will shine (1.81ct) and another one that will not (1.75ct). Hopefully that helps you make a decision.

 

[tyty333]

You can request idealscope images of these stones and see how well they are returning light. They usually like to do 3 stones at once
so you might pick another stones that falls in the 2 or under range for the HCA.

If I new what your max budget is we could help find you one.
Perhaps an AGS000 stone.
http://www.jamesallen.com/loose-diamonds/round-cut/1.75-carat-h-color-vs2-clarity-ideal-cut-sku-387428

 

[ivany]

Here is some info about HCA: http://www.goodoldgold.com/gia_ex_consumers_beware.html