So confused on girdle...

[ashmc]

Hi all,

We are looking at a round solitaire...1.52 c, GIA certified, Very Good cut, SI1, G color. Great looking diamond. It is beautiful, actually. The proportions are all really good (as far as depth and table and symmetry)...but then I saw extremely thin to thin on the girdle and it freaked me out. We have a deposit on it, but can still make a change. My diamond person (I had already left when I freaked about it), said that the extremely thin part (under a loop) is one small part and then the rest is pretty much thin. He says that it will be fine and I trust him, but I'm also very nervous. I would be devastated if it chipped. It will be a in a 6 prong setting, for what that is worth. I have googled and scared myself to death, honestly. This is an upgrade that we have been waiting to do for years and decided to bite the bullet and do it, but I don't want to make a bad decision. Any help would be much appreciated!

 

[crbl999]

I would avoid extremely thin girdles. There is a risk the diamond will chip during setting the stone or with daily wear. Since your jeweler thinks this is fine, I would recommend doing business with someone else. I would also stick with GIA excellent cut that falls within AGS ideal proportions. The fancy show room lights make that poor performing stone (very good cut) look amazing. When you take it in a variety of lighting environments you will see it is a dud.

 

[tyty333]

Can you post the GIA report so we can have a look at the numbers?

 

[Kaycee2018]

Can’t speak to the girdle concern, but GIA‘s Very Good cuts are generally not very good. There are some rare exceptions, but for the most part they aren’t recommended here on PS. Have you viewed the stone IRL and in various normal, every day lighting? Jewelry store lighting, which is designed to make even poor quality diamonds sparkle. Did you run the proportions through the HCA calculator? A copy of the GIA report (or the certificate number) and a macro pics and/or video would be helpful.

 

[Kya]

I would avoid extremely thin girdles. There is a risk the diamond will chip during setting the stone or with daily wear. Since your jeweler thinks this is fine, I would recommend doing business with someone else. I would also stick with GIA excellent cut that falls within AGS ideal proportions. The fancy show room lights make that poor performing stone (very good cut) look amazing. When you take it in a variety of lighting environments you will see it is a dud.

This.

 

[caolsen]

Real world (not PS world) there are a LOT of thin girdle stones floating around out there, especially in older cuts, that are fine. Yes, it could chip on setting. But a SI1 stone could also fracture if the inclusion is whacked the right way. Very thin can be an issue, yes, but so could the clarity if we’re talking future potential damage.

If you trust your jeweler, that’s a big help but I would ask to see the section that’s VT in a loupe to confirm it’s very limited in size and doesn’t impact large portions of the girlde. But please bear in mind, diamonds can and do get damaged. Six prongs will certainly help protect any stone, versus four.

As for the cut issue, a GIA very good can be great but yeah, but it can also be average light performance wise. I’d not reject it out of hand for that reason but any diamond does benefit from being seen in a variety of light. You can’t judge IRL light performance solely in a showroom.

PS standards for rounds are extremely high, like the the concourse de elegance of vintage car high. Just know that 99% of the round diamonds you see IRL would fail the PS standard test. That said, 99% of the diamonds IRL are not duds.

 

[Wink]

Virtually all diamonds need to be looked at with YOUR eyes, to see if YOU like it.

Unfortunately, even many GIA excellent cuts aren't what most of us would consider as stones we would proudly offer to a loved one. It is one of my biggest disappointments with GIA. The fact they cannot come up with a cut grading system that the public can rely on is a huge disappointment to those of us in the trade who want to see the cutters forced to cut for beauty rather than weight retention.

 

[Karl_K]

my take on it is, yea its an issue and there are literally thousands of RBs out there on the market so why spend the money on a common type with issues?

A truly antique stone or something awesome yea then weigh the risk vs reward but for the common RB just throw it back for another.

 

[John Pollard]

Just know that 99% of the round diamonds you see IRL would fail the PS standard test. That said, 99% of the diamonds IRL are not duds.

Statistically speaking, around 20% of diamonds with the GIA Excellent grade, offered online, will also receive Excellent on the HCA - that's the Holloway Cut Adviser on PS for causal readers.

I'd also mention not to throw away GIA VG without further info. GIA's system has a notoriously deep center. There are appealing shallow combos, capable of HCA Excellent and even AGS Ideal, which GIA grades VG.

 

[crbl999]

Statistically speaking, around 20% of diamonds with the GIA Excellent grade, offered online, will also receive Excellent on the HCA - that's the Holloway Cut Adviser on PS for causal readers.

I'd also mention not to throw away GIA VG without further info. GIA's system has a notoriously deep center. There are appealing shallow combos, capable of HCA Excellent and even AGS Ideal, which GIA grades VG.

@John Pollard interesting statistics on the GIA Excellent grade stones. What percent of VG stones fall into Excellent HCA or AGS Ideal?

 

[John Pollard]

@John Pollard interesting statistics on the GIA Excellent grade stones. What percent of VG stones fall into Excellent HCA or AGS Ideal?

From the latest data, approximately 15% of VG diamonds in the PS search were HCA EX. That number needs context, however.

Most round brilliants passing through GIA earn the Excellent cut grade. Good, Fair and Poor cuts generally make up >5% of available diamonds. While VG is better represented, the number is still fractional compared to the pool of diamonds earning Excellent.

Relevant info:
https://www.pricescope.com/education/diamond-certification/diamond-ratings#chart

 

[DejaWiz]

From the latest data, approximately 15% of VG diamonds in the PS search were HCA EX. That number needs context, however.

Most round brilliants passing through GIA earn the Excellent cut grade. Good, Fair and Poor cuts generally make up >5% of available diamonds. While VG is better represented, the number is still fractional compared to the pool of diamonds earning Excellent.

Relevant info:
https://www.pricescope.com/education/diamond-certification/diamond-ratings#chart

Love this!
Great resource for us to use to assist in explaining to those seeking advice/help that not all GIA X/3X diamonds are truly what we would consider "excellent"...here at PS, anyway.