How Much Does VG Polish Affect an Otherwise Ideal Cut Stone?

[Andelain]

Here's the example I'm looking at. An AGSO, with a nice ASET and IS, but an AGS2 because of polish. How much do you think the less than ideal polish would affect this stone's beauty?

 

[Andelain]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Anyone?

 

[Karl_K]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Properly graded not at all in the vast majority of cases.

 

[WinkHPD]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Here's the example I'm looking at. An AGSO, with a nice ASET and IS, but an AGS2 because of polish. How much do you think the less than ideal polish would affect this stone's beauty?

This can happen because one or more facets refuses to accept the top quality finish, while the light performance grade may still remain a 0. The AGS2 overall cut grade is a real deal killer on paper, but in reality it will not be noticeable to the eye in most cases.

Karl pretty much nailed it.

Wink

 

[Andelain]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Thanks, both of you for that info. That's in line with my thoughts here. I know neither of you can comment on the actual stone, so maybe some non-trade people could weigh in?

 

[WinkHPD]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

I do not see any link to the actual stone here.

Wink

 

[SHOWBIZ]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Not sure this will help you any, but the diamond with the idealscope you commented on in my post just now has VG polish, so hopefully any affect isn't significant enough to notice

 

[Andelain]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

I do not see any link to the actual stone here.

Wink

That's because I'm too doped up to proof my posts worth a lick!

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2645094.htm

 

[John P]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

For what it's worth: The GIA allows both EX and VG polish and symmetry to qualify for their top cut grade - because of what Karl and Wink have posted. Based on the proportions reported, it could be a GIA EX (as well as AGS 0 light performance) if GIA were to assess the polish as VG.

 

[Andelain]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Karl_K, I'm not sure what you meant. You think maybe AGS graded too harshly or something? I'm a bit confused.

For what it's worth: The GIA allows both EX and VG polish and symmetry to qualify for their top cut grade - because of what Karl and Wink have posted. Based on the proportions reported, it could be a GIA EX (as well as AGS 0 light performance) if GIA were to assess the polish as VG.

Hmmm, that's something I didn't know. It make sense, though. AGS has such a tight top grade in comparison to GIA that I can see them not wanting a less than great polish job to 'taint' the Ideal grade. Thank you for your input.



OK, to anyone curious, the verdict is in.

SCORE!!!!

This is what Bob said..


"I just had a conversation with your new gem and it is alive and well.

You need a gem microscope to see the reason the polish is very good. You cannot see it with our eyes or a 10x loupe. When you look through the diamond at the facets on the other side you can see some polishing lines on a facet. It does not interfere with the light return or the beauty.

It is a beautiful diamond."

And...

"I have attached the hearts image for that diamond. If the polish was Ideal it would be an ACA.

For some reason the cutter could not get a perfect polish on that facet or I am very sure they would have.

Diamonds do not always cooperate when being cut or polished."


So it seems that one facet knocked over 35% off the price.

 

[Karl_K]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

Karl_K, I'm not sure what you meant. You think maybe AGS graded too harshly or something? I'm a bit confused.

As you found out no issues.
It is better to never say never because there might be an exception some day which is why I worded it that way.
AGS and GIA for that matter do a pretty good job of grading but they are not infallible.

 

[Karl_K]

Re: How Much Does VG Polish Affect an Otherwise Ideal Cut St

OK, to anyone curious, the verdict is in.

SCORE!!!!

......

So it seems that one facet knocked over 35% off the price.

Congrates!!