Girdle Thickness

[diamond_lookr]

I''m in the market for a princess. I''ve been using the DIY Cut Grading on gemappraisers.com to compare stones. A lot of stones score 1As and 1Bs in every catagory, but the girdle thickness grades out very low and drops the overall grade. I don''t understand how girdle thickness affects cut.

 

[Jennifer5973]

Personally, I look for a medium girdle for durability and weight efficiency--you don't want a think one b/c you are losing diameter because weight is lost in the thick girlde...but a very thin girdle can chip easily (I have a stone with a very thin girdle and it did chip over time).

As for girdle's affect on the cut porportions/symmetry/brilliance, etc., one of the experts here will have to weigh in.

 

[diamond_lookr]

It seems that the girdle thickness is often listed as "very thin to slightly thick" or "thin to very thick", etc. I hardly ever see the girdle thickness listed as simply "medium" or "thin." How can the girdle vary so much?

 

[moremoremore]

I think the girdle is the least of your problems...

As a princess fan, as long as the girdle isn't too thin in an area where it could cause a chip...I don't much care about the girdle!!! I even don't care about very thick (sorry Jen!

)...you might lose a little weight, but you reduce the chance of chipping...Sometimes, it's not really a huge deal where only a small part of the girdle is maybe X thin or thin...I agree with Jennifer that I generally avoid X thin girdles...but the key is to find out where it is X thin...

But that said, do you want a grade on the cut chart or do you want a beautiful stone? A 1 A or 1 B is no guarantee....ESPECIALLY with fancies....The chart is a guide only......Who really cares if the girdle (durability and size issues aside) drops the grade...Princess stones are really impossible to judge by the numbers alone...and remember...it's not important that all aspects of the stone fall into say 1 A or 1B...but it's how certain of those aspects interact with eachother. For example, a 68 table and 64 depth are 1A....but that is not the first stone I'd call in...I would gamble for a shallow crown...Not for sure...but a decent chance...It's not just the depth and table but the relationship b/w the two (and the crown and pavillion angles that GOG told me was critical...)...

Is your head going to explode yet?

 

[Jennifer5973]

MMM, I actually agree--if it's a great stone and the girdle is a little thick,, what are we talking about? .1 or .2 mm in difference in spread? Can the eye see that minute of a difference? (I am asking seriously--always been curous about that--I know mine can't tell)

You have to look at fancies carefully and take the numbers/stats into account but train your eye as well...fancies are so tricky...As long as the girdle isn't super thin, it shouldn't be a main concern.

But let's be honest--MMM is THE princess authority! If I ever get a princess, i am just hiring her to find it....I couldn't take the stress!

 

[quaeritur]

Does the variance in girdle thickness on a given stone matter as much for a princess as a RB? Actually, I don't even know what that would do for an RB's performance, but I've stayed away from variances of more than one "grade" -ie. not very thin to very thick, but thin to medium would be ok with me.

Just curious...

 

[moremoremore]

INTERESTING question!!!! I would love to know the answer!

 

[MelanieC]

And while we are on the subject of girdles, which is better:

thin to medium say something AGS .9 to 1.5

or medium to slightly thick- something like 1.7-2.7 on AGS cert

 

[Rank Amateur]

A thicker girdle adds to the stone's weight without increasing its apparent size. This is not good because you pay for the weight, and maybe even a special premium if the extra weight hidden in the girdle just gets it over a benchmark weight (such as 1.00 ct). A very thin girdle is great for weight but needs the eye of a pro to tell if it is dangerously thin. Girdles with large variances need to be given the hairy eyeball as well. A goofy girdle might be righting and otherwise lopsided stone.

The girdle grade factors are not so much for light return or "performance" as for value and durability. The girdle has only a small effect on the stone's light return.

 

[diamond_lookr]

Does the girdle on this stone raise red flags with anyone?

Whiteflash has the Sarin posted on this stone, but I don't understand how to interprept the girdle reading section of the sarin report.

http://www.whiteflash.com/princess/Princess-cut-diamond-548856.htm#

 

[moremoremore]

Don't love the X thin to Very thick...but more importantly, that's a shallow crown ..first clue is how large the table is and compared to the depth...and I don't think the stone would have that much potential...not that it wouldn't be pretty....