calling all cut geeks

[monkey]

anyone know how to get an idea of the cut from a GIA cert, before sending it our for the full workup???
is there a mathematical formula or something to figure out the crown and pavillion angles?
i would just like to have an idea of the stones cut before sending it off for the full apraisal. . .sarin analysis, b scope etc.
thanks to anyone who can help me!

 

[monkey]

thanks linda
i just don't know if my vendor will have a sarin report. what if they don't? any other way of getting that info?

 

[hoorray]

Hi Monkey,

I was able to get a sarin report on very stone I inquired on. (I think the manufactures supplied them to the vendor if the vendor didn't have the stone on hand.) If you can't get a Sarin report, I'd find out why. I don't know if there are good, legit reasons to not have one, but I had no problem, and inquired on a lot of stones from a lot of vendors before I settled on one.

good luck!

 

[Mara]

There is no way to figure out the crown and pav angles without the Sarin report. If you have one angle I think you can figure out the other, but I'm not even sure about that. Definitely request a Sarin, it may be available or the jeweler may be able to get one. I had no problem getting Sarins on the stones we were looking at offline. I made it a pre-requisite for further stone consideration.

Good luck!

 

[monkey]

thanks everyone, that really helps. i think i'll call the GIA,maybe they can give out the info, even if its for a small fee!

 

[Rhino]

If you can get that info from GIA you will be the first consumer in the history of GIA to be able to attain it. I think your efforts to find out the info via that route will be in vain.

Rhino

 

[hoorray]

I think Rhino is right. I was told (or read somewhere) that GIA will only release that info the the vendor who submitted the stone to them for certification. When I asked vendors to try to get this from the GIA, they were very resistant. Maybe your vendor can send the stone somewhere to have a sarin report done if they can't do one.

 

[aljdewey]

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On 8/14/2003 12:37:27 PM hoorray wrote:
I was told (or read somewhere) that GIA will only release that info the the vendor who submitted the stone to them for certification. When I asked vendors to try to get this from the GIA, they were very resistant
----------------
I do believe as well that they will only release it to the vendor who submitted the stone.

They were resistant, Hoorray? REALLY? Gee, that's amazing (and terribly short-sighted). That's totally out of line, in my opinion. If I asked a vendor for information that he could readily obtain with a simple phone call and he seemed resistant, I'd walk and take my business elsewhere. There are too many good vendors here who are the epitome of customer service, who will bend over backward to give you the information needed to make a smart purchase.

 

[hoorray]

Agreed Al. and I did walk away. This occured mostly in the NY diamond district, before we started shopping on line. It never came up with on-line vendors because they always had a sarin report available.

 

[monkey]

why then do many people say the GIA is better when it doesn't give the info???

 

[dimonbob]

GIA is older but not better. AGS is equil to GIA when it comes to grading plus they additionally provide all the cutting information a Sarin report provides. When you get an Ideal grade on an AGS certificate you are getting something a GIA cert with a Sarin together does not give you. A GIA diamond with all the right Sarin numbers does not make an AGS Ideal. Close but no cigar. If you want the real deal, you need a diamond with an AGS Diamond Grading Report (cert).

 

[hoorray]

So Diamondbob,

What is the difference from an AGS 0 certed diamond, and a GIA certed diamonds with EX/EX sym and polish and a sarin that reports AGS 0 proportions? Is it the accuracy level of Sarin reports?

 

[aljdewey]

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On 8/14/2003 1:19

9 PM monkey wrote:

why then do many people say the GIA is better when it doesn't give the info???

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GIA isn't "better" per se than AGS; both give fairly accurate gradings. GIA has long been recognized as the "authority" on diamonds.

It's also important to realize that the diamond is goes through materially the same evaluation with GIA or AGS....GIA takes all the same measurements that AGS does. The only difference is that GIA doesn't list those crown/pav angles on their reports, and AGS does.

Keep in mind that the consumer is much, MUCH more educated today than previously. That information may not have been in much demand previously, and GIA didn't see fit to list it. I think they should seriously reconsider their posture on this, though, and begin providing those angles. Many more consumers are basing part of their purchasing decisions on that information.

 

[Mara]

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On 8/14/2003 1:40:52 PM dimonbob wrote:

GIA is older but not better. AGS is equil to GIA when it comes to grading plus they additionally provide all the cutting information a Sarin report provides. When you get an Ideal grade on an AGS certificate you are getting something a GIA cert with a Sarin together does not give you. A GIA diamond with all the right Sarin numbers does not make an AGS Ideal. Close but no cigar. If you want the real deal, you need a diamond with an AGS Diamond Grading Report (cert).

----------------

So if you have a GIA certed stone with EX EX pol/sym and excellent Sarin results...you still would think that the AGS graded '0' stone would be better? Why? Because it says so on the cert? We have plugged in many an AGS 0 stone into the HCA to find that it scores around a 4-5 on the HCA. Not that the HCA is the final say on a stone's beauty, but I also do not think that the AGS is either. There are many factors that contribute to a stone's beauty and reaching the pinnacle of that 'ideal make' and it's not just the grading report stating AGS 0 or an HCA score or an EX EX on p/s, etc. We all know this...we see it daily on the board in numbers posted on many stones, and those in the industry see it hands on daily I am sure as well.

In my opinion a GIA cert with the 'right Sarin numbers' means *more* than the printing of 'Ideal' or 0 on an AGS cert. The AGS cert with an 'ideal' grade doesn't really mean a whole lot unless that stone also performs well under the IdealScope and/or on the Bscope and then also the HCA. There are more tools than just a cert nowadays, people should take advantage of them and not rely on a grading lab, regardless of whether it's GIA or AGS, to tell them what the stone's make is. Otherwise the inscribing of 'Tolowsky Ideal Cut' on an EGL 63% depth stone would be given much more clout than it is...in these circles anyway.

I definitely don't think that those who are buying GIA reported stones with good Sarin's are getting anything less than they would if they bought a stone certed by the AGS--just because AGS puts the angles on there doesn't mean much except some extra ink.

My two cents...

 

[DBOF]

How well a stone is cut can`t always be judged by external measurements either. To get the crown and pavilion angles this can be done by the vendor or supplier who has invested in the equipment to provide the info. Even with this info the numbers aren`t a guarantee of how a stone will preform or *LOOK*. Also the machines that measure these angles aren`t perfect either, so you can have different sarin readings on the same stone on different sarins as well as the same machine too. This is well known in the industry. This is why a visual inspection is important.
Another thing too, is that not all stones that fall within the A.G.S. O will look the same either, they all vary and should be judged individually. Even the hearts & arrows type stones will vary from stone to stone.
We have had instances with stones graded by G.I.A. a Very good on polish & symmetry, that when submitted to A.G.S.L ended up with an Ideal on polish & symmetry. Both are good labs, and I would suggest maybe finding someone that could maybe help you in obtaining any addtional info.
Good luck in getting the crown/pavilion angles from G.I.A. I had one customer that was able to get this and even where it was cut in Antwerp. He had three sets of Sarin info

Mine -G.I.A.- and the appraisers too.

Brad

 

[dimonbob]

I think you guys got off the subject a little. Nobody said anything about how this or that diamond "performs". That is a different subject.
The subject at hand is a GIA EX EX with a Sarin report AGS0
vs a AGS Ideal. Both of them COULD be equil but the GIA diamond may not meet AGS standards. The huge difference in how these diamonds are graded is the AGS grades off for misshapen facets, facets not pointing up, misalignment of crown and pavilion. Any of these can and does keep a diamond from becoming an Ideal cut.
We at Whiteflash realize that not all AGS Ideal cut diamonds perform the same. That is why we have our own standards which are within the AGS standards. This gives our diamonds better consistency than just regular Ideals.

 

[aljdewey]

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On 8/14/2003 5:37:57 PM dimonbob wrote:
I think you guys got off the subject a little. Nobody said anything about how this or that diamond
performs.
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I think you also got off the subject a bit, Bob. The subject at hand was not originally "what's better - GIA or AGS?"

The topic was "how can I get the crown/pav angles on GIA stones" and "why do people consider GIA certs better if they don't provide that information?"

And, to a degree, yes this discussion IS about diamond performance. People asking about crown/pav angles are looking to determine how well cut a stone is, which is often a good indicator of how well might perform. Not always.....as DBOF will be the first to tell you......but within reasonable expectations.

 

[Richard Sherwood]

-----------
The subject at hand is a GIA EX EX with a Sarin report AGS0 vs a AGS Ideal.
Both of them COULD be equil but the GIA diamond may not meet AGS standards.
The huge difference in how these diamonds are graded is the AGS grades off
for misshapen facets, facets not pointing up, misalignment of crown and pavilion.
Any of these can and does keep a diamond from becoming an Ideal cut.
-----------

But these same factors would keep the diamond from receiving a GIA "excellent" on symmetry.

 

[DBOF]

Hope we didn`t get off topic

aljdewey will straighten me out

Anyhow I think both labs are good, and have no problem with either. G.I.A. has not adopted a cut grade system, but they are working on it and it involves a whole lot of research including observation testing as well. Maybe by 2004 the new reports will be in effect . A.G.S.L is working on revamping theirs as well.
As far as I know G.I.A. grades symmetry in a similar way for meet point facet alighnment of pavilion & crown,centering of table/culet,girdle, etc.
I find some customers that prefer G.I.A or A.G.S. or even both sometimes

Recently had two different stones with G.I.A. ideal proportions Excellent on polish & symmetry that on a request we had sent to A.G.S. , and both arrived at the same color/ clarity and graded A.G.S. 0. Sometimes labs can differ though, it is still subjective.

Also I forgot to mention that some appraisers can provide a sarin without a full workup for a small fee, if you can`t get one from the vendor/supplier. I think I remember one of the appraisers on here mentioning this. You can check with him or her

.

Brad

 

[aljdewey]

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On 8/14/2003 6:58:44 PM DBOF wrote:
Hope we didn`t get off topic

aljdewey will straighten me out

Brad----------------

Ahhhhhh......finally.....FINALLY, I am getting my due recognition as the subject adherence police!

Don't make me come over there! (spoken sternly, like my parents used to when they told me to sit still and I was fidgeting.)

ROTFLMAO..........what a hoot!

Brad, it's GREAT to have you guys here! Thanks for the levity you bring!