Girdle thickness

[gordypc]

I am close to pulling the trigger on a diamond. I have narrowed my search down to several ideal cut diamonds. However, I'm still not clear on the girdle thickness of some of them. Several of them have girdle sizes described in terms of thin to slightly thick, which I understand is good. However, some of the diamonds have the girdle described in numeric terms. One is 1.2 - 1.9. Another is .7 - 1.0. The third is 1.2 - 1.5. When the girdle is stated in numeric terms, what should I be looking for on an otherwise ideal diamond?

 

[pricescope]

Hi Gordypc,

Different labs use different systems for girdle thickness: GIA measures mm while AGS %.

If your numbers are from AGS report, then they are:

0.7% - 1.0% - Thin
1.2% - 1.9% - Medium-Sl.Thick
1.2% - 1.5% - Medium



GIA
Extremely thin 0.00 - 0.08 mm
Very thin 0.08 - 0.12 mm
Thin 0.12 - 0.15 mm
Medium 0.15 - 0.20 mm
Slightly thick 0.20 - 0.23 mm
Thick 0.23 - 0.33 mm
Very thick 0.33 - 0.40 mm
Extremely Thick: greater than 0.40 millimeters

AGS
Very thin 0.091 - 0.50%
Thin 0.51 - 1.2%
Medium 1.21 - 1.7%
Slightly thick 1.71 - 2.95%
Thick 2.96 - 4.2%
Very thick 4.21 - 5.7%
Extremely Thick: >= 5.71 %

HRD
Ex.Thin 0.0 - 0.5%
Very Thin 0.5 - 1.5%
Thin 1.5 - 2.5%
Medium 2.5 - 4.5%
Sl.Thick 4.5 - 6.0%
Thick 6.0 - 7.5%
Very Thick 7.5 - 8.0%
Ex. Thick 8.0 - 100%

 

[cool_rock]

Leonid,




Why is there two difference AGS "systems" for girdle thickness??

 

[pyramid]

Why is the HRD percentage for say a medium girdle so much more than the AGS percentage for medium girdle?

I know they are different labs but does anyone know their reasoning for this? Are diamonds in Europe cut with thicker girdles to prevent damage?

 

[Rank Amateur]

HRD measures girdle thickness differently.

If I remember right Garry prefers the HRD method.