How does colour grading from the GIA and AGS labs compare?

[haagen_dazs]

Hi all
This paper was written in 2004
http://grading.pricescope.com/color-clarity.aspx

As of late,I was wondering how do the diamond colour grading compare for GIA and AGS labs?
Is AGS occasionally little softer in their grading?
Are they comparable?

( It would be great if appraiser can give their input since you guys see so many stones from these labs pass through you

)

 

[stone-cold11]

Comparable probably, but since the present color grade is created by GIA, every other labs will be adjusting to what GIA says is a certain color and thus GIA will never ''technically'' be wrong on color.

 

[Lorelei]

Date: 10/13/2009 2:06:15 AM
Author:haagen_dazs
Hi all
This paper was written in 2004
http://grading.pricescope.com/color-clarity.aspx

As of late,I was wondering how do the diamond colour grading compare for GIA and AGS labs?
Is AGS occasionally little softer in their grading?
Are they comparable?

( It would be great if appraiser can give their input since you guys see so many stones from these labs pass through you

)

It would indeed be best to have the appraisers answer as they have real experience with this, but I have heard AGS were slightly softer on colour at one time, I don't know if this is still the case but I think not.

 

[haagen_dazs]

It would indeed be best to have the appraisers answer as they have real experience with this, but I have heard AGS were slightly softer on colour at one time, I don''t know if this is still the case but I think not.

yeah i want to verify this...
where are all the appraisers !!

 

[elle_chris]

My appraiser usually disagrees with the AGS grade by 1. Or has in the past. But he''s also known for being tough on color. But, my GIA stones have graded the same.

 

[bgray]

I have stones graded by EGL USA, GIA, AGS and HRD. My observation is this:

EGL=fairly soft across the board
GIA=strict on color but not as strict on clarity
AGS=softer on color but tougher on clarity and of course cut
HRD=hard on color and clarity nothing on cut (i.e.stricter than all other labs)

 

[oldminer]

I can nearly always give credence to GIA and AGS reports. Once in a while they miss the mark, but not by much. Dealers tend to toss away the harshly graded "errors" and love to promote the slightly "softer" graded errors as better deals. It all averages out. I am not familiar enough with HRD to judge.

Every other lab in the USA is a secondary or tertiary player and you just do your own grading with such reports if you know how to do the grading properly. Reliance on other than GIA-AGS has a higher risk element, but as we found out some years ago, it has a higher reward elelement once in a while too. It is not all bad news when it comes to secondary lab reports. There are a few roses among the many thorns which some consumers do manage to find. It just depends on what level of research and investigation you wish to go through to get the right stone at the right price.

 

[Lorelei]

Date: 10/13/2009 11:27:28 AM
Author: oldminer
I can nearly always give credence to GIA and AGS reports. Once in a while they miss the mark, but not by much. Dealers tend to toss away the harshly graded ''errors'' and love to promote the slightly ''softer'' graded errors as better deals. It all averages out. I am not familiar enough with HRD to judge.

Every other lab in the USA is a secondary or tertiary player and you just do your own grading with such reports if you know how to do the grading properly. Reliance on other than GIA-AGS has a higher risk element, but as we found out some years ago, it has a higher reward elelement once in a while too. It is not all bad news when it comes to secondary lab reports. There are a few roses among the many thorns which some consumers do manage to find. It just depends on what level of research and investigation you wish to go through to get the right stone at the right price.

Thanks for the reply David, very helpful!

 

[haagen_dazs]

Date: 10/13/2009 10:55:13 AM
Author: elle_chris
My appraiser usually disagrees with the AGS grade by 1.

hi elle.
could you clarify please?
is the grading difference higher or lower? ie AGS is more or less strict compared to your appraiser?

thanks

 

[haagen_dazs]

bump! for more appraisers and vendors to weigh in on this topic

 

[Kelli]

My diamond was graded an I by the GIA, then was recut and sent to the AGS, where it was called an H. I like the AGS''s cut grading better though.

 

[haagen_dazs]

interesting..
its not a fair comparison of the same stone between 2 labs since recutting was involved.
i was told that when a stone is being cut from rough to a diamond, the colour can change (depending on how its cut and what is cut away)


thanks for sharing though

 

[Todd Gray]

Date: 10/15/2009 11:01:29 PM
Author: Kelli
My diamond was graded an I by the GIA, then was recut and sent to the AGS, where it was called an H. I like the AGS''s cut grading better though.

Re-cutting a diamond can alter the color grade because as Mark noted, diamond color can change ''in layers'' as the diamond is cut... The best analogy I can provide is ''peeling an onion'' or ''sanding wood''. However it should also be noted that the difference between ''H'' and ''I'' color is slight and that a difference like that could occur within the same diamond grading laboratory depending on who graded the diamond - if the difference were something more like "it was a ''G'' at GIA and a ''J'' at AGS" there would be a reason for concern.