Steep pavilion but beautiful stone?

[j3rry333]

Hi all! My girlfriend (soon-to-be fiancee!) found a setting she loves at Brilliant Earth. It's stunning, fits her style perfectly, and is unlike anything I have seen elsewhere. Brilliant Earth won't sell the setting without the diamond, so I'm looking to buy a stone from them as well. After visiting the showroom twice, I put down a refundable deposit on a .82 carat GIA D VS2 diamond. Here are the specs:

Cut Grade: Excellent
Polish: Very Good
Symmetry: Excellent

Depth: 61.8%
Table: 57%
Crown angle: 34.5 degrees
Crown height: 15%
Pavilion angle: 41.2 degrees
Pavilion depth: 43.5%
Star length: 50%
Lower half: 80%
Girdle: thin-medium, faceted, 3.5%
Culet: none

I popped it into the HCA and got a 3.3 or 2.4 depending on whether I entered C/P angle or percent. I assume the HCA is dinging the stone for its steep pavilion angle, since all the other numbers seem pretty good. From what I've read, the pavilion angle can have a huge impact on light return, and theoretically, this stone is in danger of having light leakage under the table.

The thing is though, I compared the stone to two others with HCA scores under 2, examining them in spotlighting, outdoor light coming through a window, under a regular floor lamp, and while cupping my hand over the stones, and I really couldn't say that this stone was any darker or less sparkly than the others. In fact, I liked it more than the other two because I loved the icy white of the D color compared to the F and E color of the other two (I'm very color sensitive) and because the others were both S12s with very slightly visible inclusions that bothered me. Apart from that, it appealed to my eye in a way that's hard to describe - very clean, vivid, and alive looking. The other two stones were both beautiful and bright, but they weren't quite as intriguing to me somehow.

Now that I've put down a deposit, though, the HCA score and pavilion angle are starting to really worry me. I'm not a trained gemologist with years of experience looking at diamonds, so I feel that I can't necessarily trust my first impressions. I looked at the diamond in a limited number of lighting environments while it was resting on a white tray, not set in a ring. The diamonds I compared it to were subtly but noticeably warmer to me, which definitely affected my preference.

I guess my question is, how likely is this diamond to be a high performer given its specs? Is it possible that there could be visible leakage/darkness under the table that I would not have noticed in the showroom while it was sitting on a white tray? Are there other potential problems with a steep pavilion that I do not even know to look for?

Thanks for your help in advance!

 

[MissGotRocks]

Double check the crown angle you typed in here - is it a typo?

 

[j3rry333]

Double check the crown angle you typed in here - is it a typo?

Oops, thanks! I fixed it.

Crown angle = 34.5 degrees, not 43.5!

 

[Karl_K]

hca is overly harsh on pavilions over 41.
As long as they all stay under 41.4 and the mains lower girdle/halves angles and crown angles all match they can be top notch diamonds.
With the gia rounding there is room for this to be one such.
When you get into this range the numbers are really meaningless we need is/aset images to tell you anything.

 

[Lorelei]

hca is overly harsh on pavilions over 41.
As long as they all stay under 41.4 and the mains lower girdle/halves angles and crown angles all match they can be top notch diamonds.
With the gia rounding there is room for this to be one such.
When you get into this range the numbers are really meaningless we need is/aset images to tell you anything.

Hi J3rry,

As Karl mentions, images would be the next step so we could tell you more, I am not sure if this seller offers them though? If you wanted to get a larger diamond, you have some wiggle room on the colour and clarity specs, but this is a personal choice, just a suggestion.

 

[proto]

I had understood that 41.4 is the magic number before colour entrapment becomes a significant issue.

That said, I also understand that many cutters avoid cutting a stone beyond 41.0.

What is the reason for this? Is it only to obtain good HCA values?

 

[MissGotRocks]

No, it is to achieve the best light performance out of a stone. Diamond cutters know parameters to try and achieve top AGS or GIA certed stones - not all of them are aware or influenced by the HCA.

 

[j3rry333]

Thanks for your input, everyone. Brilliant Earth does not provide images, unfortunately

As for the color and clarity, I was initially looking for a G S12 based on the advice I read here. I think I must have loupes for eyes, though, because I couldn't find a single one that was eye clean to me, even though I had a gemologist check them over first Then the saleslady brought in a D color and I was ruined for anything else. The icy white color is so beautiful I can't resist!

 

[Lorelei]

Thanks for your input, everyone. Brilliant Earth does not provide images, unfortunately

As for the color and clarity, I was initially looking for a G S12 based on the advice I read here. I think I must have loupes for eyes, though, because I couldn't find a single one that was eye clean to me, even though I had a gemologist check them over first Then the saleslady brought in a D color and I was ruined for anything else. The icy white color is so beautiful I can't resist!

LOL! Some do, certainly not me I hasten to add, I used to have loupes for eyes but that was a long time ago. It might be that you have to raise the clarity grade and that SI2 won't suit, but you might find one that does if you keep looking. At least you now know what you like best, maybe D E F colour and SI1+ might be a good place to start if you have a strong preference for colourless diamonds, especially as you have viewed G in person.

 

[Karl_K]

I had understood that 41.4 is the magic number before colour entrapment becomes a significant issue.

That said, I also understand that many cutters avoid cutting a stone beyond 41.0.

What is the reason for this? Is it only to obtain good HCA values?

When you go beyond 41 you have to be careful in the angles not to go over and match everything up, at one time that cutting and measuring precision was not available.
It is now and is fairly common making for more acceptable over 41 pavilion diamonds.
At one time there was no way of knowing if a facet was 41.2 or 41.5 because of the accuracy of the tools so the rule became stay under 41 on the gauges available at the time.