Negative impact of girdle thickness variation

[GBK]

I am looking at an F VVS2 3.04 ct Princess diamond which measures 69.3% depth 72% table on GIA and 69.1% 71.2% on Sarin. The crown height is 10.7%. My concern is that GIA describes the girdle as "very thin to thick" though the Sarin report describes the girdle thickness as 3.1% (3.0-3.3). I do not know how to interpret the latter description but if that is a range of 3.0% to 3.3%, it doesn''t sound too bad. Are the two descriptions inconsistent and should I be concerned about reduced brilliance and valuation because of the girdle irregularity?

 

[oldminer]

Such a girdle thickness does not set the value.... However, we avoid super thin girldes when we can. Possibly there is only a very small zone of thinness, likely on one of the pointed corners and not along a full side edge. A thin pointed corner is fragile during setting more than anything. This kind of breakage is common with princess cuts, so be cautious. Let the seller do the setting work as this is the only person who will be responsible in case of breakage during setting.

A sarin can give average girdle thickness, where the GIA may give the thinnest and thickest range. The actual average may be anywhere in between the thickest and thinnest.

 

[GBK]

Thanks for your comments. If the girdle thickness is mostly a safety concern and does not have effect on the value, why do they list "very thin to thick" as "2B" in grading criteria? And, are you saying that Sarin measurs girdle at only a few sample spots and then provides the range? Is 3.0 to 3.3% a fairly consistent range?

 

[oldminer]

Sarin gives an "average" but does not fully examine or recognize every area, especially the pointed zones. It can miss a very thin area if it is a small in length.

The AGA Cut Class charts address the range of thinnest to thickest, but mostly the decrease in cut quality has to do with fragility when too thin or heaviness when too thick. The decreases or increases in cut quality are slight and judgmental, and hardly moves the price point of a decently overall cut stone. It is a fine and gray line between a super cut diamond and a pretty good cut diamond. The AGA Cut Class grades help people to make those decisions.