Expert Opinion Please - Two Stones

[horatio76]

I am having trouble deciding between two stones that I have looked at:

AGS#: 6725101
Report Type: Diamond Quality™ Document
Shape and Style: Round Brilliant
Measurements: 6.39 - 6.42 x 3.99 mm
Cut Grade: AGS Ideal 0
Light Performance: 0
Proportion Factors: 0
Finish: 0
Polish: Ideal
Symmetry: Ideal
Color Grade: AGS 1.0 (F)
Clarity Grade: AGS 3 (VS1)
Carat Weight: 1.014
Fluorescence: Negligible
Comments:
Table: 57.0%
Crown Angle: 35.5
Crown Height: 15.5%
Girdle: Faceted, 1.7% to 4.0%
Pavilion Angle: 41.0
Pavilion Depth: 43.2%
Total Depth: 62.2%
Culet: Pointed
HCA Rating: 3.9
Quoted price of $9,300 with white gold setting with 2 - 6 point diamonds on each side.

EGL USA Certificate 83353307D
Weight 1.06 ct.
Shape ROUND BRILLIANT
Color F
Clarity VS2
Measurements 6.55 - 6.51 x 4.06 mm
Depth 62.2
Table 57.0
Crown 15.3
Pavilion 43.0
Girdle THIN TO MEDIUM
Polish GOOD
Symmetry GOOD
Fluorescence NONE
Culet NONE
HCA Rating: 2
Quoted price of $8,200 with white gold setting with 2 - 6 point diamonds on each side.

I''m slightly confused why the AGS stone, which is considered ideal in some instances would have a worse HCA rating than the EGL USA stone.

I am leaning towards the AGS Stone but I just want some reassurance from someone in the know. I just want to make sure the AGS stone will be a good choice from a performance perspective (sparkle, etc).

Thank you very much for your help. Much appreciated.

 

[Lorelei]

Bump for Horatio, he would like one of the experts to advise him please, Garry, JQ etc.

 

[Paul-Antwerp]

F-VS1 is in average about 15% more expensive than F-VS2. That already covers the price-difference.

HCA on the EGL is based upon percentages, which is less exact than angles. However, average numbers look the same, so light performance could be similar. With AGS, the grade is based on the full stone however, while with the EGL-stone, we can only judge upon the average parameters.

Other factors do also apply, but that would lead us into more detail.

But the summary is that the AGS-stone in my eyes looks cheaper than the EGL-stone, because of the higher clarity. With the re-assurance that AGS is extremely strict on clarity.

Live long,

 

[Lorelei]

Thanks Paul!

 

[Ellen]

Paul, thank you for helping!


You say between the two, light performance could be the similar. But what exactly would that be, in a best guestimate?

Specifically enquired by him:

I am leaning towards the AGS Stone but I just want some reassurance from someone in the know. I just want to make sure the AGS stone will be a good choice from a performance perspective (sparkle, etc).

To me, it (the AGS) looks like a steep/deep, and my thinking, and post to him in an earlier thread, was that he could do better. No?

 

[Paul-Antwerp]

Ellen,

The OP asks for an opinion between two stones. As such, performance-wise, the AGS-stone is not worse than the EGL-stone, but the EGL-stone could be worse than the AGS. Price-wise, because of the clarity-difference, the AGS-stone looks cheaper.

Of course, this is not the best possible combo within AGS-0 light performance, and clearly, one can find better performing AGS-stones. But to me, that is not the question.

Live long,

 

[Ellen]

To me, he asked both. However, the part I highlighted was written in statement form, but I took it''s meaning as a question.

i.e. Is this AGS stone a good choice performance wise?


But maybe I read it differently than it was intended.

 

[horatio76]

Ellen, your assumption was correct. I was also wondering "Is this AGS stone a good choice performance wise?" Paul, can you respond to this question?

Thank you everyone for your input.

 

[Paul-Antwerp]

Whether AGS ideal light performance is ''good enough'', is very difficult to answer.

Within AGS-0, you still have various levels of light performance, and this particular stone is probably not in the very top-group. But for fear of passing the line of self-promotion, it is very difficult for me to go into further detail.

Live long,

 

[Ellen]

horatio, if you want to continue looking, here is a guideline that John Q from Whiteflash posted. While in the post it talks about GIA, this would apply to AGS as well. It is somewhat of a balancing act between crown and pavillion angles. If one goes to "the edge"on an angle, the other must counterbalance, to get great optics.

For instance, my stone has a 41 PA, but, it''s coupled with a 34.05 crown angle. And that''s as it should be, because 41 is at the edge, so that crown angle compensates in the other direction. One is deep, the other towards shallow. Your stone has two "deeps", which can cause light leakage. It may perform "ok", but there are other combos that will perform better.

And lastly, that AGS stone is just over the 1 ct. mark, by a hair. You are paying that premium, but it is not facing up as big as it should.

Honestly, I don''t mean to sit here and pick on you and your stone. But I KNOW you can get better, especially paying for an AGS premium. I just want you to end up with a really pretty stone.

Here is your cheat sheet, second post down. On the 40.8 PA, you can go with everything inbetween 34-35, usually. He only gives three angles, because GIA rounds.

I hope this helps, as it was meant to.