Should I spend close to 12k on this diamond?

[KC-BBQ]

Okay diamond experts. Please provide thoughts on this diamond's specs and what i should be cautious / aware of? Starting price is 12k.... advice? I attached the HCA below also.
1.93 Ct. Ideal
Table: 57.4%
Crown Angle: 36.4
Crown Height: 15.7%
Girdle: Faceted, 1.1% to 4.1%
Pavilion Angle: 40.9
Pavilion Depth: 43.3%
Star Length: 53%
Lower Girdle Length: 79%
Total Depth: 61.7%
Culet: Pointed
hca_cut_advisor.png (229.18 KiB) Viewed 31 times

 

[Gypsy]

Pass. Bad numbers.

 

[Gypsy]

The entire purpose of faceting a diamond is to reflect light.
How well or how poorly a diamond does this determines how beautiful it is.
How well a diamond performs is determined by the angles and cutting. This is why we say cut is king.
No other factor: not color, not clarity has as much of an impact on the appearance of a diamond as its cut. An ideal H will out white a poorly cut F. And GIA Ex is not enough.
So how to we ensure that we have the right angles and cutting to get the light performance we want?
https://www.pricescope.com/wiki/diamonds/diamond-cut
Well one method is to start with a GIA Ex, and then apply the HCA to it. YOU DO NOT USE HCA for AGS0 stones.
https://www.pricescope.com/wiki/diamonds/holloway-cut-advisor
The HCA is a rejection tool. Not a selection tool. It uses 4 data points to make a rudimentary call on how the diamond may perform.
If the diamond passes then you know that you are in the right zone in terms of angles for light performance. Under 2 is a pass. Under 2.5-2.1 is a maybe. Over 2.5 is a no. No score under 2 is better than any other.
Is that enough? Not really.
So what you need is a way to check actual light performance of your actual stone.
That's what an idealscope image does. https://www.pricescope.com/wiki/diamonds/firescope-idealscope
It shows you how and wear your diamond is reflecting light, how well it is going at it, and where you are losing light return. That is why you won't see us recommending Blue Nile, as they do not provide idealscope images for their diamonds. James Allen and WF do.

The Idealscope is the 'selection tool'. Not the HCA.
So yes, with a GIA stone you need the idealscope images. Or you can buy an idealscope yourself and take it in to the jeweler you are working with to check the stones yourself. Or if you have a good return policy (full refund minimum 7 days) then you can buy the idealscope, buy the stone, and do it at home.

 

[KenD]

What lab certified this stone?
What is its clarity?
What is its color?
What is its rating for polish?
What is its rating for symmetry?

I have very limited experience, but:
It surprises me that this stone could be rated as "Ideal" with its crown angle of 36.4 deg.
Related to girdle numbers, a range of 1.1 to 4.1 seem high (but I have even less experience in this area).

 

[KC-BBQ]

Thank you for the information. The stone specs were from its AGS Lab report. Does that make a difference in your analysis?

Thank you.

 

[teobdl]

What's the AGS cut grade?

 

[KC-BBQ]

What lab certified this stone? AGS
What is its clarity? SI2
What is its color? H
What is its rating for polish? Ideal
What is its rating for symmetry? Ideal

1.932 Ct. Ideal
7.99 - 8.01 x 4.93 mm
Cut: AGS Ideal
H, SI2
Light Performance: 0
Proportion Factors: 0
Finish: 0
Polish: Ideal
Symmetry: Ideal
Table: 57.4%
Crown Angle: 36.4
Crown Height: 15.7%
Girdle: Faceted, 1.1% to 4.1%
Pavilion Angle: 40.9
Pavilion Depth: 43.3%
Star Length: 53%
Lower Girdle Length: 79%
Total Depth: 61.7%
Culet: Pointed

 

[KC-BBQ]

1.932 Ct. Ideal
7.99 - 8.01 x 4.93 mm
Cut: AGS Ideal
H, SI2
Light Performance: 0
Proportion Factors: 0
Finish: 0
Polish: Ideal
Symmetry: Ideal
Table: 57.4%
Crown Angle: 36.4
Crown Height: 15.7%
Girdle: Faceted, 1.1% to 4.1%
Pavilion Angle: 40.9
Pavilion Depth: 43.3%
Star Length: 53%
Lower Girdle Length: 79%
Total Depth: 61.7%
Culet: Pointed

 

[teobdl]

Love it. Super fiery. Not as much white light but AGS says it's ideal so it'll be stunning. Nice price. Make sure it's eye clean.

 

[KC-BBQ]

So why would GYPSY above say pass. Was she thinking it was GIA specs? ... and why would that make such a difference?

Thank you Teobdl

 

[teobdl]

It absolutely is a steep crown angle. This combo of angles fits into a small slice of Ags diamonds that meet ideal criteria. I'm not sure it would be Gia excellent cut. If you look on the HCA you'll see that there's a small group of Ags ideal (bottom right corner) with high crowns that aren't also Gia excellent.

Ags evaluates that diamond in its merits alone and sees whether it meets it's criteria, which is the strictest in the business. The high crown will give the diamond a certain flavor--more fire and less white light return than one with a lower crown. Just know that that's what you're getting. But the ags grade tells you that for what it is, this diamond is a fireball.

 

[John P]

So why would GYPSY above say pass. Was she thinking it was GIA specs? ... and why would that make such a difference?

On its face those numbers aren't frequently seen for fine-make diamonds.

This is a combination at the edge of a cutting-cliff, meaning that a tic in one direction or another could quickly have turned it to AGS 2 3 or even 4 in performance. 40.9/36.5 is predicted AGS 2-3 performance. 41.0/36.3 is predicted 3-4.

I suspect that the producer who executed it was adept, well-tooled and understands the AGSL system, including the appropriate minor facet combinations, cut-precision (and possibly some custom brillianteering) to assure the AGS0. In cutting terms, I'd even say he/she was showing off. And since this is an edge combination with GIA too, on the verge of EX-VG, this feat of derring-do was executed without a safety net.

I'd buy him or her a Stella-Artois if I knew who did it.

 

[John P]

The high crown will give the diamond a certain flavor--more fire and less white light return than one with a lower crown. Just know that that's what you're getting. But the ags grade tells you that for what it is, this diamond is a fireball.

Cartier was cutting this kind of combination regularly for their center-stones some time ago. They'd produce these high crowns and aim directional fiber-optic LEDs at them inside the cases and the dispay would explode with dispersion.

The edge of the cutting cliff, in this case, would have been a reduction in brightness below 0 all the way to 234 if the cutter had missed. He didn't. In that sense "fireball" is exactly right. The dispersion score is likely maxed, while the brightness score may not be as high as you'd expect in a pure-Tolkowsky, but it's high enough to remain in the top performance grade.

 

[TC1987]

Thanks for the info, John Pollard. It's always great to hear insider information from the pros.

 

[John P]

Thanks for the info, John Pollard. It's always great to hear insider information from the pros.

TC, I love this stuff. It's nice to have folks like you, Gypsy and teobdl around - who truly "get it" and enjoy the dialogue on these topics.

PS: KC-BBQ's avatar is making me hungry.

 

[KC-BBQ]

given the combination at the edge of a cutting-cliff, and ~max dispersion/fire. Would this stone's value to the owner be laregly diminished by setting it in a halo?

 

[LLJsmom]

The high crown will give the diamond a certain flavor--more fire and less white light return than one with a lower crown. Just know that that's what you're getting. But the ags grade tells you that for what it is, this diamond is a fireball.

Cartier was cutting this kind of combination regularly for their center-stones some time ago. They'd produce these high crowns and aim directional fiber-optic LEDs at them inside the cases and the dispay would explode with dispersion.

The edge of the cutting cliff, in this case, would have been a reduction in brightness below 0 all the way to 234 if the cutter had missed. He didn't. In that sense "fireball" is exactly right. The dispersion score is likely maxed, while the brightness score may not be as high as you'd expect in a pure-Tolkowsky, but it's high enough to remain in the top performance grade.

This is cool stuff!! Thanks for explaining John.

 

[John P]

given the combination at the edge of a cutting-cliff, and ~max dispersion/fire. Would this stone's value to the owner be laregly diminished by setting it in a halo?

I think it would be amazing in a halo. Make sure the small stones are well-cut and compliment the color... Sure. Surround it with even more brightness.

RE: The picture... Oh man. You're killing me.

 

[Gypsy]

So why would GYPSY above say pass. Was she thinking it was GIA specs? ... and why would that make such a difference?

On its face those numbers aren't frequently seen for fine-make diamonds.

This is a combination at the edge of a cutting-cliff, meaning that a tic in one direction or another could quickly have turned it to AGS 2 3 or even 4 in performance. 40.9/36.5 is predicted AGS 2-3 performance. 41.0/36.3 is predicted 3-4.

Pretty much why I said pass. If you had said it was an AGS0 I would have said it had potential. But I thought it was GIA, and since GIA rounds there was too much risk of it being a bad performer given the HCA.

Sounds like you've got a winner though. Enjoy it.

And send some of that BBQ over here!

 

[luvdajules]

Given John Pollard's evaluation and description, I think you found a very stone. Some people look for this type of fireball specifically, no so easy to find though! And at the price point for nearly 2 ct, very nice find indeed. Good luck with whatever you decide. How do you plan to set it? Halo? If you want a nice but still reasonably priced Halo, Gypsy suggested to another poster the Ritani one for about $1800. The whole effect will be huge!

 

[KenD]

So why would GYPSY above say pass. Was she thinking it was GIA specs? ... and why would that make such a difference?

Thank you Teobdl

In fairness to Gypsy, she had said, "Well one method is to start with a GIA Ex, and then apply the HCA to it. YOU DO NOT USE HCA for AGS0 stones.
https://www.pricescope.com/wiki/diamonds/holloway-cut-advisor""""

Your stone is just such a stone ("AGS0").

Have you seen the stone or any images of the stone, yet?
Is it eye clean?
It seems that this stone could sell for much more than $12 K. I wonder if there is a reason that it isn't.

 

[KenD]

Also, what is the fluorescence of the stone?

 

[SB621]

The high crown will give the diamond a certain flavor--more fire and less white light return than one with a lower crown. Just know that that's what you're getting. But the ags grade tells you that for what it is, this diamond is a fireball.

Cartier was cutting this kind of combination regularly for their center-stones some time ago. They'd produce these high crowns and aim directional fiber-optic LEDs at them inside the cases and the dispay would explode with dispersion.

The edge of the cutting cliff, in this case, would have been a reduction in brightness below 0 all the way to 234 if the cutter had missed. He didn't. In that sense "fireball" is exactly right. The dispersion score is likely maxed, while the brightness score may not be as high as you'd expect in a pure-Tolkowsky, but it's high enough to remain in the top performance grade.

Thank you John! I miss your comments on PS! It's nice to learn something new on PS again! I also love Cartier and never knew this about them. Interesting stuff!

 

[Dreamer_D]

I err on the side or trusting AGS cut grading. I think this one is worth more evaluation -- real life photos, optical assessment imagery -- the price is very good. Where is the grade setting inclusion? Will you see it in person?

 

[luvdajules]

Don't forget what someone else pointed out already, check for eye clean from the vendor and what that means to them and if that's okay by you. If you halo it first, sight unseen, you might get stuck with a non-returnable "custom" order. It is an Si2 after all, and if it's truly eye clean, you got lucky cause you're not paying for something you can't see.

 

[KC-BBQ]

I have seen it in person and I didn't see any markings. It was set, so it could have been disquising something but I looked at it for a while. It was really amazing in person. I'm going to look at it again tonight so let me know if there are any concrens I should be asking the jewler about. .... I am also attaching some photos when I first saw it.

Thank you all for such a great learning experience.
GYPSY: I now understand your comment and thank you
Teobdl: Thank you for getting the fireball going
John Pollard: Thank you for the detailed description, it is very informative and educational.

 

[KC-BBQ]

KenD

Fluorescence: Negligible
Comments: Additional clouds are not shown.

 

[John P]

Thank you John! I miss your comments on PS! It's nice to learn something new on PS again! I also love Cartier and never knew this about them. Interesting stuff!

Thanks for saying something. It's my pleasure. I made a new year's resolution to engage more with PS in 2014. It's a great site for dialogue and learning. RE Cartier: This thread inspires me to check them out again. A lot has changed, industry-wide, in the last few years.

John Pollard: Thank you for the detailed description, it is very informative and educational.

You're welcome. I'm excited for your project, and glad to help a fellow BBQ lover. I visit Lockhart TX as much as possible

 

[Gypsy]

KC. The prongs could be hiding something. I'd want to see it unset before I bought it. And I'd want to loupe it. They jeweler will have a loupe and will show you how to use it.

 

[yssie]

Okay, I'm lost!

John, I agree that the cutter must have been very adept! But how can we guess to what purpose was he showing off, if indeed he was? Was it merely to create an edge-case AGS0? (ie. what do you see here that I don't, and can I coax you into sharing it? )
And of course the bigger question is whether this type of edge-case AGS0 matches OP's definition of "beautiful".

Here's an edge-case AGS0 that I would definitely want more info on, for example:
**mod note: edited by request**