Symmetry & Polish confusion...

[arnotke]

I know they aren''t primary determining factors for selecting a diamond but I''m confused about the rating scale for symmetry and polish.

From what I''d read, I thought the scale was:

EX, VG, Good, Fair, Poor

Last night I was looking at some diamonds that had Ideal as the rating. Where does this fit in? Are the GIA and AGS scales the same?

Thanks in advance.

 

[phoenixgirl]

No, the GIA uses "excellent" for its highest grade, while the AGS uses "ideal." Same thing.

 

[fuffi]

AGS and GIA grading systems differ. AGS includes ideal in their grading scale while GIA's highest grade is excellent.

 

[arnotke]

Thanks for your help. So, for clarity, does AGS go ID, EX, VG, etc. or does it just exclude EX?

Thanks for your help.

 

[WinkHPD]

Id ex vg

It is confusing and many of us in the trade are not too happy about it, but it is the way that it is. The difference between Ideal, ex and vg is not visible to the eyea but it takes a great deal more work to get the Ex or Ideal ranking, depending on which lab is doing your grading. It is unfortunate that both labs do not use the same ranking for their top rank.

Wink

 

[arnotke]

Got it. Thanks very much for your help.

 

[glitterata]

So is an AGS ideal the equivalent of a GIA excellent, or are the excellents the same and ideal is an added category at the very top? I"m assuming the former, right?

Or are some GIA ex's AGS ideals and other GIA ex's are AGS ex's?