appropriate girdle?

Greta2002, girdle doesn't affect diamond performance very much.

From tutorial:

Girdle thickness should ideally be between thin, medium and slightly thick. There is almost always some variation in girdle thickness around a stone. There are often four small, thin areas reflecting the original shape of the octahedral rough diamond crystal. These thin areas should not be set in a claw setting in an exposed position because they are also cleavage directions. If a diamond is struck in these directions on extremely thin to thin girdles they can and will chip.

Diamonds with thick, very thick, or extremely thick girdles weigh considerably more but may be much better buys. There will be small amounts of light loss when viewed in some directions.

Diamonds with very thin girdles are not recommended for claw set ring settings but are OK in pendants and earrings. There is always the risk of a girdle chipping during setting if it is too thin.

Can you provide definitions for very thin, thin, etc.?

Thanks

from Marty Haske site for GIA:

Thin: Less than 0.15 millimeters
Medium: between 0.15 and 0.20 millimeters
Slightly Thick: between 0.20 and 0.23 millimeters
Thick: between 0.23 and 0.33 millimeters
Very Thick: between 0.33 and 0.40 millimeters
Extremely Thick: greater than 0.40 millimeters

AGS and HRD have different systems and use girdle %

By the way, how would a consumer know if a diamond is or is not set at the proper position on the girdle? Is there any indication that I would look for, or is this something that needs to be brought up to the person setting the stone (and hoping he/she does it right)?

Thanks,

Caratgirl