GIA Nears Release of Diamond Cut Grading System

[mike04456]

GIA Nears Release of Diamond Cut Grading System

 

[sumi]

Hmmm..interesting.

Do you think this is a good thing for consumers, or do you think it can be used as yet another way to confuse the average consumer? I suppose educating consumers on the value of cut is always a good thing.

 

[pricescope]

Good find, LG.

"The new GIA Diamond Cut Grading system will apply only to standard round brilliant diamonds on the D to Z color grading scale from Flawless to I3. Modified rounds, fancy shapes and fancy color diamonds will not be included for now..."

 

[Nicrez]

Correct me if I am wrong, but in the article, it stated that this grading would help cutters cut stones more effectively, and thus be better for the consumer, price-wise.

Price is mostly determined by carat, when all things are equal, such as color and clarity of a stone that can never change, no matter how it's cut. Yes the stone can be cut better and command more, but it would also most likely be cut SMALLER, and a 2.03 would then be a 1.9, and slightly lower on the RAP. Would the cut difference really make the stone MORE valuable than the same say F, VS1 at 2.03 carats?

Is this just another thing that diamond sellers will use to peddle smaller stones with lower color and greater inclusions and request higher prices than before, now that it's "measured" by GIA?

Also, no FANCIES?! Isn't that the stone category that needs this cut grading system the MOST?! *GROAN*

 

[mike04456]

I think more information is always good for the consumer.




There is no cut grade for fancies now because there really is very little consensus about cut in that area. I expect, though, that someone will come out with one to meet the demand. I think AGS is working on it.

 

[Patty]

I think this is great news.

 

[Nicrez]

Don't get me wrong, I think it's a great thing, and a long time coming, but really only useful to round stone people.

Certainly, now people will be forced to learn more about a stone's cut, which is subjective. Either people can get more confused, or they can get more knowledgeable.

Let's hope for the latter!

 

[aljdewey]

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On 2/6/2004 2:43:21 PM Nicrez wrote:





Certainly, now people will be forced to learn more about a stone's cut, which is subjective----------------

I disagree, Nicrez. People cannot be forced to consider or learn anything if they feel it is extraneous.

The bulk of people will continue to follow the credo beat into them by their jewelers about the 4Cs, and they won't ask questions about cut unless someone tries to explain that diamond A is priced higher than diamond B because of its make.

That probably happens now; there is just nothing on paper with the grading report to substantiate the claim, and now there will be.

Incidentally, color and clarity is subjective too, so this isn't breaking new ground. In fact, the make of a stone (based on angles/measurements) is likely to be LESS subjective than assigning color/clarity values.

 

[Garry H (Cut Nut)]

You can understand how cutters will get a better yield on some types of rough if you read this

http://www.diamond-cut.com.au/23_bicfic.htm
The BIC's yield better from octahedral stones sawn in half, or when the top smaller part is cut to a BIC.

FIC's yiled well from examples like rounded dodecahedra shown here.
http://diamonds.pricescope.com/carat.asp

Some of you might be aware that I have been telling peope for many years that diamonds with these specs that are currently discounted will go up in value once the GIA releases its system.

There are some other intracies to do with lower girdle lengths - Generally FIC's look better with longer, and BIC's are better with shorter.

 

[pqcollectibles]

I think it's interesting that GIA took 10 years to validate what I've already learned on PS. Not every diamond that fits the Tolkowsky Ideal parameters will be a great performer. Diamonds that don't fit the Tolkowsky Ideal can be great performers.

We see examples on a routine basis. Great HCA scores from diamonds that do not have Ideal specs, with very satisfied buyers that rave about performance.

 

[strash]

you are right!!! i have seen diamonds that are ideal cut and they appeared dark and didnt look too good. but most are good looking. i have seen a lot of diamonds that arent ideal and they blow those ideal cuts away and look fantastic.

 

[mike04456]

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On 2/6/2004 6:11:36 PM pqcollectibles wrote:





I think it's interesting that GIA took 10 years to validate what I've already learned on PS. Not every diamond that fits the Tolkowsky Ideal parameters will be a great performer. Diamonds that don't fit the Tolkowsky Ideal can be great performers.

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

There's a difference between a general feeling and scientific evidence. The latter is what's taken GIA so long to gather. The problem is slipperier than it might appear.

 

[pqcollectibles]

Point well taken, LawGem. I don't have empirical evidence as it were. Just personal observations.

 

[Rank Amateur]

----------------
On 2/6/2004 6:44:41 PM LawGem wrote:

----------------
On 2/6/2004 6:11:36 PM pqcollectibles wrote:



I think it's interesting that GIA took 10 years to validate what I've already learned on PS. Not every diamond that fits the Tolkowsky Ideal parameters will be a great performer. Diamonds that don't fit the Tolkowsky Ideal can be great performers.

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

There's a difference between a general feeling and scientific evidence. The latter is what's taken GIA so long to gather. The problem is slipperier than it might appear.

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

A goodly share of that slippery-ness comes from the grease on their palms.

 

[valeria101]

I think this is good news all the way. Diamond cut would be the first purely manufactured (positive)quality ever entering any gem grades...

Until now, most new comers here would not factor in any other parameters but those on a GIA cert as "quality" factors. if "cut" suddenly appears there, it would be a huge step... no matter what the foundation of GIA grading is.

Nicrez, if a 2ct stone needs to go down to 1.9 and get a great cut instead of sloppy, who needs the extra 0.1 anyway ? And the pricing by carat is already a myth - just look at the spread of retail prices for one set of GIA grades (shape-carat-color-clarity that is) and no further proof is needed. The Rap reads the market, but does not make it; a new grading system by the most influential arbiter out there will.

PS is great, but it does not have that kind of authority, yet

A GIA cut grades may really open widely this Pandora's box, and no extra diamond would go out in dust, that's for sure. Only Garry's cut receipes may gain terrain, that's all...

 

[oldminer]

The GIA is going to make an impact with their grading no matter how good, or weak, the system they create is. They are the industry leader and will have researched the effects of their process BEFORE they release the system. No doubt, because of great concern for their main customers, DIAMOND CUTTERS and DIAMOND SELLERS, the system will have some potential for bias that favors the trade....Now in respect to more diamond at better prices, this may happen, but in respect to simply finer cut diamonds without consideration of price, that scenario may not be so likely. People who seek the very best perfoming diamonds may or may not be so well served.
We will wait and see.

LawGem: In spite of no devices quite yet ready to grade fancy shaped diamonds for cut quality, fine shape AND brilliancy, the AGA Cut Class stystem for fancy shaped diamonds has been available for use since the mid-1990's.
It has been adopted by the NAJA with over 700 members who appraise jewelry and applied on numerous websites other than my own for assisting people in determining when a fancy shaped diamond is well cut for size appearance, durability and shape. While it does not grade brilliancy, it is my belief that no matter how the brilliancy readings of advanced euqipment turn out, that SHAPE is of such great importance in fancy shaped stones, that there is no way for the regular fancy shapes of fine cut to be greatly different than those parameters already in the AGA Cut Class charts.

To say that a big part of cut grading for fancy shaped diamonds has not been done is to ignore many years of use and expert examination of these already existing and much used parameters. I fully expect more detailed analysis to come in all aspects of grading diamonds, but there are some very meaningful portions of cut grading of fancy shapes that are probably going to be just about perfect for a long time to come.

For those that are not familiar with the AGA Cut Class charts they are on the web for you to use, explore and question. You can grade diamonds with known parameters for free, too.

I think the very long time it has taken GIA to come to a conclusion is very indicitive of the attitiude of diamond dealers who would rather leave the buyers somewhat blind rather than informed. It could be that they's love to have another ten year grace period for fancy shapes to be graded. They may not be so lucky. Maybe I am wrong on this point, but I can't help but suspect that this subject could have been addressed more rapidly had it seemed a priority of the GIA's main clients. And I truly feel it is not a main prioirty for most of them. They would prefer the status quo.

 

[Superidealist]

----------------
From the article:


The traditional Ideal cut will no doubt fall into GIA's top cut category...
----------------

If this is the case, it sounds like the new system will be too grainy for the average Pricescope consumer. The conventional wisdom here seems to be that not all ideals are created equal but, according to the article, we can expect these to all be given top marks.

 

[oldminer]

Just a couple more thoughts on this topic. It is one of my special areas of interest.

Do you think the GIA will offer the cut grade of previously measured and examined diamonds to those who now have GIA reports at no cost? I very much doubt it. Will the cost be nominal or on the high side? I'd bet to the high side if history can be used to make a judgment.

Will those folks who have the data needed to make a GIA cut grade be able to go somewhere on the Internet or in a software program to find out what the cut grade is or will the ONLY source of the cut grade be the GIA Lab itself? I would think the GIA will make it a very private methodology, but I could be wrong.

I suppose their defense is you don't invest ten years of research to give it away, but as a non-profit entity supported by those in the trade, the information really is property of those who paid for it if not actually, then morally. Sharing the result of ten years of effort, supported by the trade, but then offering only to sell the grading service is not a very good return to the trade on their investment.

I hope that dealers, sight holders, cutters and the public will have access to the process of cut grading offered by the GIA. It will be very interesting to me how this new process will be introduced and to whose benefit.

 

[strmrdr]

oldminer,

When I got a few minutes I was going to post here that Im highly skeptical
that it would be something that would serve the consumers over the suppliers/dealers.

Im glad Im not the only one that feels that way.
Like you said time will tell.

 

[Garry H (Cut Nut)]

----------------
On 2/8/2004 11:06:51 AM oldminer wrote:

Just a couple more thoughts on this topic. It is one of my special areas of interest.

Do you think the GIA will offer the cut grade of previously measured and examined diamonds to those who now have GIA reports at no cost? I very much doubt it. Will the cost be nominal or on the high side? I'd bet to the high side if history can be used to make a judgment.

Will those folks who have the data needed to make a GIA cut grade be able to go somewhere on the Internet or in a software program to find out what the cut grade is or will the ONLY source of the cut grade be the GIA Lab itself? I would think the GIA will make it a very private methodology, but I could be wrong.

I suppose their defense is you don't invest ten years of research to give it away, but as a non-profit entity supported by those in the trade, the information really is property of those who paid for it if not actually, then morally. Sharing the result of ten years of effort, supported by the trade, but then offering only to sell the grading service is not a very good return to the trade on their investment.

I hope that dealers, sight holders, cutters and the public will have access to the process of cut grading offered by the GIA. It will be very interesting to me how this new process will be introduced and to whose benefit.----------------

Great questions Dave - you always come at things with a common sense but left of field.
Cutters will of course need to know what parameters to cut, and GIA will use sarin to assess the cut, just as AGA and AGS currently do. Now there will also be additional minor facet data in the new systems - so it would stand to reason that there will be some "trading off" like there is now with GIA stones listed as AGS 0's etc.

But if GIA are smart like Sergey they would scan the stone and analyse the light performance (potential) which is proportion dependant, but with propietary software (like Sergey's will one day be when labs only have the full blown DC cut grading software. That way the symmetry is accounted for in one analysis

Dave i still have not got back to you about your AGA round system and where it would likely fall in the GIA system. I am sure your top grade stones will be the top grade - but your system would peanlise the say 29crown angle 41.6 pavilion with a 58 table and short lower girdles - the gIA will probably give it a agreat grade. As you once said to me Dave - these off makes might look nice, but they look different and will take some market adjustment. GIA have that impetus and can change the market. For that I will be very thankful