Is cut grading science or opinion?

[Rockdiamond]

Copied from another thread to give this subject an independent conversation

Date: 3/10/2010 10:52:16 AM
Author: Paul-Antwerp
GIA''s and AGS''s cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only.


Live long,

To start, here''s the definition of "Science" from dictionary.com

sci·ence   [sahy-uhns] Show IPA
–noun
1.
a branch of knowledge or study dealing with a body of facts or truths systematically arranged and showing the operation of general laws: the mathematical sciences.
2.
systematic knowledge of the physical or material world gained through observation and experimentation.
3.
any of the branches of natural or physical science.
4.
systematized knowledge in general.
5.
knowledge, as of facts or principles; knowledge gained by systematic study.
6.
a particular branch of knowledge.
7.
skill, esp. reflecting a precise application of facts or principles; proficiency.

It''s rather ambiguous in relation to this conversation. But if we consider point 1- where the words "facts or truths" are used, that will get my point across.
First, you are grouping GIA and AGS cut grading with ASET and HCA. Clearly the trade does not view these items in the same group.
I believe we can all agree that there are valid experts in the field of diamonds who respect GIA and AGSL cut grading, but do not feel that ASET IS and HCA provide meaningful results.
But even if we eliminate the HCA/IS and ASET, GIA''s cut grade is a combination of scientific research combined with human observation. That aspect may be obtained and organized scientifically, but the opinions themselves are not science- they are opinions.

Is it a "fact" or "truth" that a stone getting a better score on the HCA is "better cut" than another lower scoring stone?
The answer here is clear- no.


Is it a fact that ASET can measure light return? Yes, I believe it is.
However the relevance of this information is not clear, nor can it''s relevance be inferred to be a scientific indicator of beauty.
Besides the fact that ASET measures a stationary stone, which will never be viewed in such a manner in real life, it''s not agreed that increased light return equals increased beauty.

Science allows Paul to cut consistently gorgeous stones, in that I agree- but it does not allow us to judge these stones "better cut" than others that may also garner similar cut grades from GIA or AGSL, yet have different angles and measurements which are inherently different than what Paul cuts.

 

[oldminer]

"Is it a fact that ASET can measure light return? Yes, I believe it is."


On the above point, I'd say you are wrong and that is a misunderstanding on your part because you have the wrong idea in mind about the definition of the word "measure". An ASET tool measures nothing. It shows an image which subjectively purports to show the quality of the light return. I think subjectively it succeeds, but that it is not anything close to a "measurement".

I do believe many of us would agree that there are numerous configurations which create beautiful diamonds and that some folks, even when shown what we deem to be an Ideal Cut, would just as soon buy some well cut stone which might not be described in standard terms as ideal cut.

"Is it a "fact" or "truth" that a stone getting a better score on the HCA is "better cut" than another lower scoring stone?
The answer here is clear- no"

I beg to differ. When used properly, as a screening tool, the HCA has a great deal of truth in its working. I don't think one should overlook a 1.2 and insist on a 0.8, but I can surely understand looking at both of them versus looking at a 2.8. One needs to understand "screening" and not using tools improperly. "Better Cut" is often used improperly, too. HCA puts some numbers out there to show a prediction of light return, but you can have a fine stone with a higher number and a poorer stone with a low number from time to time. Again, it is a screening tool for distant shoppers.

Science will be able to tell us what diamonds measure certain characteristics, but only the human mind judges subjectively the beauty. There may be a human test of a large enough group of unbiased individuals to pinpoint a good sized range of what that group finds most attractive, but that is statistical analysis and not a directly scientific, ironclad proof that some other group of folks won't find some other stone configurations also very pretty.

I think you cannot prove that what AGS has done is wrong. The AGS0 stones all look superb. What many of us suspect is that there are other possible configurations which "might" also look just as nice and seem to be well cut. This is what can happen with enough research and with Branding. So far, most cutters walk in lock step with one another as they are forced to follow the best commercial pathways available in order to get enough volume to stay in business.

You can speak about hypothetical stones, but getting market acceptance of differenly made diamonds is not a task which anyone has found easy to accomplish. If it is all hypothetical, then we will stay with the Ideal Cuts we have today as they are commercially viable and very attractive. If someone wants a different cut, there are many alternatives in the market which just are not blessed with the "Ideal" terminology. It does not limit one's choices unless they can't get past the word "Ideal". If you want a paper instead of a diamond, or a word instead of a diamond, then there are many roadblocks to free choice. If all you want is a beautiful diamond, there are far more choices in the market.

Lastly, if you examine diamonds cut by Paul, you'd find them superbly cut. You would find many other diamonds of similar weight, color and clarity cut by others not nearly as well cut. It might be symmetry, polish, and/or light return characteristics which makes the other stones less well cut. It could be they don't meet AGS0 standards, yet are indeed finely fashioned. If those competing cutters knew better, they might have chosen to cut an AGS0 because it might sell quicker.

When a seller, like yourself, argues that any diamond might be a fine cut, or that there is nothing special about today's ideal cuts, it smacks of self interest. People will find it incredible that you alone are on a different path than most of the trade. Of course, you are not alone except on Pricescope. Many traditional sellers are living with outdated ideas about what is or is not a fine make diamonds. I have struggled with these changes, but have come to the new reality. Not all of us will do that, but the path you are travelling looks like it has a "dead end" sign and that is not a good thing if you don't like the prospect of possibly backing up a long way...........

 

[Rockdiamond]

Thanks for thinking this through Dave- I really appreciate your opinions, and will respond to them.
One thing though- I am writing this as a diamond lover, not a diamond seller.
Although we have sold many round brilliant diamonds, that''s a minor part of our business.
If we were aiming to sell round brilliants in today''s market, I agree with you, I''d have to "tow the line"
The fact that we don''t sell "ideal" cut diamonds allows me a rather unique perspective.....and the luxury of having these conversations from an informed position without the stress of having to "protect" something.
It basically allows me to give a face to the majority of the trade who may feel differently- but don;t post here on PS.

 

[kenny]

 

[Lula]

Date: 3/10/2010 2:57:16 PM
Author:Rockdiamond
Copied from another thread to give this subject an independent conversation

Date: 3/10/2010 10:52:16 AM

Author: Paul-Antwerp

GIA's and AGS's cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only.



Live long,

Science allows Paul to cut consistently gorgeous stones, in that I agree- but it does not allow us to judge these stones 'better cut' than others that may also garner similar cut grades from GIA or AGSL, yet have different angles and measurements which are inherently different than what Paul cuts.

Excellent post, Dave Atlas. Very well written.

As a customer of Paul's, through one of his vendors, Wink, I feel I can attest to what consumers care about the most -- performance.

RD, I clipped the last part of your post, because this point is what I find most relevant as a consumer of diamonds. How does a consumer know that he/she has found a diamond that has a "better cut"? By living with a diamond, watching it perform, and -- this one's important -- comparing it to the other diamonds out there in stores and on other people's hands.

I have owned 3 Crafted by Infinity Diamonds, a .53 J VS2; a 1.00 M SI 2; and my current diamond -- a 1.01 I I1. With my first diamond, I did all the newbie things when I got it -- took it to an appraiser, checked the stone's HCA, put it in dark room with a match (ala Rock Doc), studied the ASET, IS, H&A images, and checked the veracity of those images with my own visual observations using my IS and H&A viewer. The stone passed all the tests. Whew!

Then I lived with the stone. And, as women who wear diamonds do, I studied it under every possible lighting condition and got to know its every little detail. And I started noticing that it looked better - not just a little better, a lot better -- than what I saw in the stores and what I saw being worn by other women.

I traded by .53 in. I studied the images, checked the HCA, etc., etc. Didn't bother with an appraiser this time. Wore the diamond. Noticed, again, that my Infinity outperformed other diamonds. In fact, I remember sending Wink an e-mail telling him that I was sometimes embarrassed to wear my ring to the local coffee shop, because the fire it threw off under the spotlights made people stare. It wasn't the only diamond in the coffee shop, but it was the only one shooting off sparks big enough to distract fellow coffee drinkers!

I traded in my M for my I I1. Spoke to Wink on the phone about the inclusions. He made me a video. I sent him my ring and had him set the diamond sight unseen. And I just realized today that I never did calculate the HCA on my latest Infinity! Hold on -- let me check. It scores a 1.1. No surprise.

I guess you could say with this third Infinity that I've been able to move beyond science because I trust that Paul's knowledge of diamond cutting (science) ensures that the cut of my Infinity is indeed "better" than the other diamonds I see in real life. And because I trust Wink as my vendor to help me find the best Infinity for my budget and my needs.

But the trust was earned, and came only after I saw with my own eyes that the science Paul uses to cut his diamonds pans out in real life performance.

 

[WinkHPD]

Date: 3/10/2010 4:13:00 PM
Author: oldminer
''Is it a fact that ASET can measure light return? Yes, I believe it is.''


On the above point, I''d say you are wrong and that is a misunderstanding on your part because you have the wrong idea in mind about the definition of the word ''measure''. An ASET tool measures nothing. It shows an image which subjectively purports to show the quality of the light return. I think subjectively it succeeds, but that it is not anything close to a ''measurement''.

I do believe many of us would agree that there are numerous configurations which create beautiful diamonds and that some folks, even when shown what we deem to be an Ideal Cut, would just as soon buy some well cut stone which might not be described in standard terms as ideal cut.

I agree with you that the ASET does not measure anything Oldminer, but I am pretty sure I disagree with what I think you are saying that it purportedly shows the quality of light return.

I believe that if you talk with the folks at the AGS laboratory you will see that the ASET was designed to, and used for, telling us where the light we are seeing is coming from!

It says nothing about the quality of that light, nor does it measure in any way. Green is coming from 0 - 45 degrees, red from 45 - 75 degrees and blue is coming from 75 to 90 degrees with leakage shown by black or white, depending on the background of the image. It is important that direct light be coming from that 45 - 75 degree range so that the head of the observer not obstruct the light coming to the diamond.

The arrows that we see in the viewers are in fact made by the obstruction of light by the observer.

At the AGS laboratory, when they are grading symmetrical stones, ie rounds or square emerald cuts, the stone will be graded for the quality of its image at 0 degrees tilt and at 15 degrees tilt to see how the stone is handling light when not being viewed from the perpendicular.

Non symmetrical stones, ie ovals, marquises, emerald cuts are viewed at 0 degrees tilt and 15 degrees tilt on both the x axis and the y axis.

This is an important concept of the ASET as it can be used in bright light, medium light or even poor light and still tell us all we need to know about how that particular stone we are looking at handles light. I think it is important that professionals in the trade know some of these things so that we can share them with the public in a non confusing way.

Oh, Rock, you question the science of the work done by the AGS, are you aware that Dr. Jose Sassian has a peer reviewed article in scientific journal that is quite extensive and way above my head on the light physics that went into the work at the AGS? His work, and the work done by the AGS was not supposition and "shucks, by golly, we think it is thisa way," it is hard science and hard work and it is worthy of a great deal of respect. You may not like it, or you may disagree with it, but please respect the intense level of work and effort that went into producing it.

Wink

 

[WinkHPD]

Date: 3/10/2010 5:18:08 PM
Author: sarap333

Date: 3/10/2010 2:57:16 PM
Author:Rockdiamond
Copied from another thread to give this subject an independent conversation

Date: 3/10/2010 10:52:16 AM

Author: Paul-Antwerp

GIA''s and AGS''s cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only.



Live long,

Science allows Paul to cut consistently gorgeous stones, in that I agree- but it does not allow us to judge these stones ''better cut'' than others that may also garner similar cut grades from GIA or AGSL, yet have different angles and measurements which are inherently different than what Paul cuts.

Excellent post, Dave Atlas. Very well written.

As a customer of Paul''s, through one of his vendors, Wink, I feel I can attest to what consumers care about the most -- performance.

RD, I clipped the last part of your post, because this point is what I find most relevant as a consumer of diamonds. How does a consumer know that he/she has found a diamond that has a ''better cut''? By living with a diamond, watching it perform, and -- this one''s important -- comparing it to the other diamonds out there in stores and on other people''s hands.

I have owned 3 Crafted by Infinity Diamonds, a .53 J VS2; a 1.00 M SI 2; and my current diamond -- a 1.01 I I1. With my first diamond, I did all the newbie things when I got it -- took it to an appraiser, checked the stone''s HCA, put it in dark room with a match (ala Rock Doc), studied the ASET, IS, H&A images, and checked the veracity of those images with my own visual observations using my IS and H&A viewer. The stone passed all the tests. Whew!

Then I lived with the stone. And, as women who wear diamonds do, I studied it under every possible lighting condition and got to know its every little detail. And I started noticing that it looked better - not just a little better, a lot better -- than what I saw in the stores and what I saw being worn by other women.

I traded by .53 in. I studied the images, checked the HCA, etc., etc. Didn''t bother with an appraiser this time. Wore the diamond. Noticed, again, that my Infinity outperformed other diamonds. In fact, I remember sending Wink an e-mail telling him that I was sometimes embarrassed to wear my ring to the local coffee shop, because the fire it threw off under the spotlights made people stare. It wasn''t the only diamond in the coffee shop, but it was the only one shooting off sparks big enough to distract fellow coffee drinkers!

I traded in my M for my I I1. Spoke to Wink on the phone about the inclusions. He made me a video. I sent him my ring and had him set the diamond sight unseen. And I just realized today that I never did calculate the HCA on my latest Infinity! Hold on -- let me check. It scores a 1.1. No surprise.

I guess you could say with this third Infinity that I''ve been able to move beyond science because I trust that Paul''s knowledge of diamond cutting (science) ensures that the cut of my Infinity is indeed ''better'' than the other diamonds I see in real life. And because I trust Wink as my vendor to help me find the best Infinity for my budget and my needs.

But the trust was earned, and came only after I saw with my own eyes that the science Paul uses to cut his diamonds pans out in real life performance.

LOL! Sometimes I wonder why I bother. I should just let other people say it better while I am working out my answer.

Wink

 

[Rockdiamond]

Dave- point taken about he use of the word "measure" to describe an ASET image.

You used the term "show the quality of light return" ...and your statement that follows seems to agree that what the ASET provides is subjective.

The AGS0 stones all look superb

That statement is totally subjective Dave- the other side of it would be calling a diamond with proportions you don''t like "bad"....which leads us to have this conversation many times. As I feel it''s important, I very much appreciate you taking the time to participate. ( sorry Ken, I missed the part where you are being forced to participate)

snip...

if you examine diamonds cut by Paul, you''d find them superbly cut. You would find many other diamonds of similar weight, color and clarity cut by others not nearly as well cut. It might be symmetry, polish, and/or light return characteristics which makes the other stones less well cut. It could be they don''t meet AGS0 standards, yet are indeed finely fashioned. If those competing cutters knew better, they might have chosen to cut an AGS0 because it might sell quicker.

I agree that it''s very likely that if I examined a stone cut by Paul, I''d feel it was very well cut- but the rest of your point is not correct. True, there''s a lot of junk out there, but there are quite a few cutters whose work is equal to Paul''s, in terms of cut quality.
Furthermore, the market does not judge stones on "light return" - rather on overall cut characteristics.
Sarap- your post was great- and also proves my point.
Wink, and Paul have proven that they can provide you with stones you love.
In essence you''re trusting what they see with their eyes or how they interpret ASET or HCA

Please don;t mistake my point- my opinion would most likely be that I love the stones Paul cuts- but it would be an opinion, not science.

 

[Rockdiamond]

Wink...to be clear: I never questioned the validity of an AGS 0 cut grade.

your explanation of ASET was a very good addition to this topic- thank you.

Also - to agree with Sara that science is used in the cutting procedure, just that any grading procedure is subjective.

 

[Stephan]

Date: 3/10/2010 5:33:28 PM
Author: Rockdiamond
Also - to agree with Sara that science is used in the cutting procedure, just that any grading procedure is subjective.

Rejecting bad diamonds, is it subjective too?
When I see a nailhead or a fisheye, I really can''t imagine that it will please a buyer.

 

[Lula]

RD, I think you are missing my point -- the consistency of Paul''s cutting allows me as a consumer to hit the bull''s eye on real life performance every time.

Paul''s stones are reliable. In science, if a test is performed several times with the same result, the results are considered to be reliable. A reliable test is a more useful test.

Paul''s stones score well on the tests which you are not a fan of, and they score well on the one thing you and I agree on -- visual beauty.

If given a choice between selecting from diamonds that perform well on the HCA, ASET, IS, etc., AND perform well in real life based on my lived experience, versus selecting from diamonds that don''t do well on the HCA, IS, ASET, etc., and taking the chance that they will perform well in real life (finding the proverbial needle in the haystack), I''ll take door number one every time.

I get a reliable product that way. I know what to expect, and the diamond delivers every time.

 

[Rockdiamond]

Sara- part of the point here is that Paul''s stones ( for example) have a particular look.
If one knows they love that look, than going back for more makes all the sense in the world.

But other stones that may not score well on HCA/ASET/IS may also get EX GIa cut grade, or AGS0.
There will be noticeable differences in the way these stones look.
Maybe it''s a hearts and arrows pattern versus a less organized sparkle- maybe it''s the look of a smaller table versus a larger one....but there are visual differences between diamonds that can be agreed by experts, to be well cut.

Is one better cut than the other if both are considered "top cut grade"?

Stephan, stones that are considered "off make" by experts will show visible deficiencies beyond the question of taste.
But there''s a huge variety of well cut stones.

 

[HVVS]

Date: 3/10/2010 4:54:14 PM
Author: kenny

Killjoy. We haven't had a good slugfest in a while.

I used to really like older cut diamonds, that have wonky symmetry, misaligned facets, strange proportions, random sparkles, and whatnot. And then I started wearing this from GOG. Once you have a superideal cut, there's no going back. I am so smitten with this H&A stone that I am sending one of my old wonky diamonds out for a recut to H&A, selling one or two others, and the remaining European cut (European, not OEC) just might find itself on the way to the cutter, too. Clean or dirty, regardless of the lighting, this H&A is stunning. I can't say that for the others.

Oh, and I'm combing the PS vendors databases for something like a .75 to .98 H&A.

No offense meant Rock Diamond, but I prefer the H&A and other modern cuts. I still like a genuine old OEC or OMC but that's about it.

 

[cara]

Date: 3/10/2010 2:57:16 PM
Author:Rockdiamond
Is cut grading science or opinion?

YES!

 

[Dancing Fire]

RD
i had and still do own some so called 60/60 stones (my wife's 3 stone ring) and in no way that anybody can convince me that these 60/60 stones are in the same league as today's H&A stones,no way!!

yes,her 3 stone ring sparkles,but not like today's top cut H&A stones,and 2 out of 3 stones do show "light leakage" around the edge under the IS.

 

[Rockdiamond]

For the purpose of identifying what''s known around here as "superideal" cuts, the tools perform flawlessly.

If my point is considered- that cut grading is necessarily based on opinion, then there has to be a range.
Stephan asked before, "Is rejecting stones subjective?" Absolutely!

Do facets have to line up perfectly to be attractive?

 

[Lula]

Date: 3/10/2010 6:51:45 PM
Author: HVVS

Date: 3/10/2010 4:54:14 PM

Author: kenny

Killjoy. We haven't had a good slugfest in a while.

I used to really like older cut diamonds, that have wonky symmetry, misaligned facets, strange proportions, random sparkles, and whatnot. And then I started wearing this from GOG. Once you have a superideal cut, there's no going back. I am so smitten with this H&A stone that I am sending one of my old wonky diamonds out for a recut to H&A, selling one or two others, and the remaining European cut (European, not OEC) just might find itself on the way to the cutter, too. Clean or dirty, regardless of the lighting, this H&A is stunning. I can't say that for the others.


Oh, and I'm combing the PS vendors databases for something like a .75 to .98 H&A.

No offense meant Rock Diamond, but I prefer the H&A and other modern cuts. I still like a genuine old OEC or OMC but that's about it.

Ditto! A good slugfest can be good for the soul.

And ditto on there's no going back.

It's more than brand loyalty. One only has to visit the SMTR thread a few times to notice that superideals just look better than stones with non-ideal proportions. In fact, I remember well the first day I found SMTR as a lurker. I hadn't for sure decided that I wanted a diamond for an anniversary ring. But after I saw the photos of ideal-cut diamonds on SMTR, I remember thinking, wow, if that's how diamonds are supposed to look, I want a diamond. You see, I had never seen an ideal-cut diamond before PS.

I chose Wink as my vendor and Infinity as my brand of superideal cut stones. But that is because I like the philosophy behind the brand, and, yes, because I like the distinctive "look" of Paul's diamonds. But if for some reason I couldn't buy an Infinity stone, I still would have chosen another super-ideal cut diamond. I would not have ventured into the "other well-cut stones" category. The simple reason being I just don't think they perform as well across all lighting conditions.

Is it the perfect symmetry, the patterned flash rather than the random flash -- yes, that's part of it. But it's more than that -- it is the ability of the super-ideal to do what it does best, reflect light and break light into white and colored flashes. I believe the science behind the super-ideal maximizes the diamond's ability to do this.

I agree with HVVS, the exception to the superideal rule in my mind is a well-cut, vintage OEC. But they are are in a category of their own, just as I believe natural fancy colored diamonds are in a category of their own.

You can't compare these stones to superideal RB's. It's not apples to apples. But you can compare superideal rounds to other rounds, and see that there are clear performance advantages to superideals. It's more than preference or opinion.

Can you find the random "well-cut non-superideal" that performs well in real life? Sure, nothing is impossible. But it would be the exception rather than the rule. With the superideal, excellent performance is the rule not the exception.

 

[Paul-Antwerp]

I just see this thread, which emerged during my night. Morning now, and the luxury of time to think things over and read carefully.

Wink and Sara, thank you for your enthusiasm, but I do not think that Infinity''s production should be discussed in this thread. Granted, we use the newest techniques to show as well as we can the quality of our work, but that does not mean that the production is based upon these techniques. Actually, the design that we are aiming for in rounds precedes most of these techniques, and is mostly based on a combination of common sense and good use of the experience of seasoned cutters, knowledge if you want. Only in the design of our princess-cuts, the preliminary studies of AGS helped, and it was the combination of AGS'' research and our knowledge that led to our design.

In that way, the new techniques and science only confirms our choices.

However, David (Rockdiamond, to avoid confusion), it is painful to see how you twisted my statement in order to attack something I did not say. Let me re-copy what I said:

Date: 3/10/2010 2:57:16 PM
Author:Rockdiamond
Copied from another thread to give this subject an independent conversation

Date: 3/10/2010 10:52:16 AM
Author: Paul-Antwerp
GIA''s and AGS''s cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only.


Live long,

I have named 5 techniques and mentioned that some are vetted by science. Having read the other posts, especially Wink''s, how can you disagree with this?

Also, I have said that they are techniques to judge potential brightness. If I say ''potential brightness'', you should not twist this into something else. ''Potential brightness'' is a very important factor in the judgment of light performance, and for many consumers in the judgment of beauty. However, it is also limited to ''potential brightness'' and not more.

Given that most of these techniques have overlapping conclusions is a strong sign of their validity. However, in the judgment of a stone, given their limitations, they are also rejection-tools. Valid rejection-tools. Unfortunately, the use of most is limited to round brilliants only.

Therefore, I would advise you to read and understand what is written, instead of twisting the words and disagreeing with the twisted words.

Live long,

 

[Stephan]

Let me play the devil''s (David''s) advocate.
All the people here advise a 34-35 crown, and they say there will be more fire than with a 32.5 crown, but ... nobody can prove it.
And in real life, shallower diamonds do have a lot of fire (that''s what my eye can see).
Look at following diamond:
http://www.jamesallen.com/diamonds/I-SI2-Ideal-Cut-Round-Diamond-1266629.asp
Is there a scientific way you can prove it is not as good as a branded diamond with a 34-35 crown (Paul, Brian, ...)?

Don''t misunderstand me, Paul''s and Brian''s diamonds are perfection, but how can you say that 34-35 crown is better than this one?

Thank you!

 

[Paul-Antwerp]

Stephan,

You might not have read my reply before you posted.

I mentioned ''potential brightness''.

Live long,

 

[Stephan]

With all the respect, but yes I did read your post.
How does it answer to the question I''ve asked?
(Sorry for being ignorant!

)
I''m not ironic, my question is serious.
Can somebody prove that the stone linked above has less potential than a commercial H&A?
I don''t even speak about brightness, because ASET says it all, I''m speakiing about the other factors.

 

[Amethyste]

Date: 3/10/2010 6:51:45 PM
Author: HVVS

Date: 3/10/2010 4:54:14 PM

Author: kenny

Killjoy. We haven't had a good slugfest in a while.

I used to really like older cut diamonds, that have wonky symmetry, misaligned facets, strange proportions, random sparkles, and whatnot. And then I started wearing this from GOG. Once you have a superideal cut, there's no going back.
.

I disagree with that, and many will too ( like Erica and Grace ands plenty of others )Well, for me I started the opposite, I had a Super ideal round J-VVS1 diamond and hmmm... It was meh. It lacked the character of the older cuts. so I went back to OECs and the likes cause they are amazingly attractive in more ways than the super ideal i had. I guess I discovered over time, tha I am more attracted to other shapes than round.

 

[caolsen]

Kenny:

Anything with Jean Luc Picard works for me!

Not thing again, Number One.

Make it so....

 

[Lula]

Sorry, Paul, you are right, we should not be talking about individual business entities here. My enthusiasm took us off topic.

And I think it's worth clarifying that it is round brilliant cuts (and Princess cuts, as Paul mentions) that qualify for AGS 000 certification. So I don't mean to malign OEC's or fancy cuts in any of my comments. They are different, and beautiful, animals, imho.

I do believe that there is science behind the AGS 000 cut grade. That said, science is developed and conducted by humans; therefore, it may contain elements of human bias and judgment.

How does science mitigate human bias and judgment?

1. By using tests that are reliable (repeating a test and getting the same results multiple times).
2. By using tests that are valid:
a) construct validity, a test that says it measures potential brightness should indeed be measuring that quality and not another quality.
b) criterion validity:
-includes using tests that predict future performance (predictive) and then assessing whether future performance did indeed match what the test predicted.
-and includes comparing the results of one test with the results of another accepted test (both measuring the same quality) to assess whether or not the two tests are highly correlated with one another (concurrent validity).

I tried to put this in layman's language and it is difficult. But, I do believe that the tests referred to over and over by prosumers on PS -- HCA, IS, ASET, H&A images -- do meet 1. and 2. above. This is science. How do you refute science, RD -- well, you develop a study that refutes the results of 1. and 2. above. So far I haven't seen that from you. I have seen you point to hypothetical outliers but no systematic study.

So to me, your argument relies on the laws of chance and luck and randomness, and I prefer to use techniques that will provide me more than just a random chance of choosing a diamond that will be a good performer.

 

[Serg]

from Oxford dictionary ;
"scientific method
noun
a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses."

from Wiki:

"Scientific method

Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning.[1] A scientific method consists of the collection of data through observation and experimentation, and the formulation and testing of hypotheses.[2]

Although procedures vary from one field of inquiry to another, identifiable features distinguish scientific inquiry from other methodologies of knowledge. Scientific researchers propose hypotheses as explanations of phenomena, and design experimental studies to test these hypotheses. These steps must be repeatable in order to dependably predict any future results. Theories that encompass wider domains of inquiry may bind many independently-derived hypotheses together in a coherent, supportive structure. This in turn may help form new hypotheses or place groups of hypotheses into context.

Among other facets shared by the various fields of inquiry is the conviction that the process be objective to reduce biased interpretations of the results. Another basic expectation is to document, archive and share all data and methodology so they are available for careful scrutiny by other scientists, thereby allowing other researchers the opportunity to verify results by attempting to reproduce them. This practice, called full disclosure, also allows statistical measures of the reliability of these data to be established."

For mine opinionDiamond industry has not infrastructure for verification and testing any hypotheses( in Cut grade field). Diamond Science community is to narrow and has not real ability for verification and science discussions. Few articles in science magazines are not science yet. All publications had NOT " all data and methodology so they are available for careful scrutiny by other scientists, thereby allowing other researchers the opportunity to verify results by attempting to reproduce them"
Most publications were just descriptions ( without any real hypotheses, testing and proof)
Science standards in Diamond industry is very very low because Diamond industry are not interesting to pay for science work. Science is not part Diamond industry.
Again my opinion what Science methods are enemy for most( may be for all)current Diamond business models.
99.9% professionals in diamond industry do not like science approach or can not understand what it is.( if we speak about CutStudy, Grading,..etc)
Science is very expensive Toy for diamond industry yet.

 

[Paul-Antwerp]

Date: 3/11/2010 7:13:32 AM
Author: QueenMum
With all the respect, but yes I did read your post.
How does it answer to the question I''ve asked?
(Sorry for being ignorant!

)
I''m not ironic, my question is serious.
Can somebody prove that the stone linked above has less potential than a commercial H&A?
I don''t even speak about brightness, because ASET says it all, I''m speakiing about the other factors.

Stephan,

My statement was the following:

"GIA''s and AGS''s cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only."

If you are talking about being the devil''s advocate, you should at least follow where the ''devil'' (sorry David, I do not see you that way, but it is part of the analogy) claims that my statement is wrong.

Nowhere in my statement can one find anything about fire, while your post only addresses fire. So, you are asking me to prove a point that I did not even put forward.

Your last sentence basically confirms my statement, although that again does not mean that I fully agree with your last sentence.

Live long,

 

[Stephan]

Date: 3/11/2010 9:44:14 AM
Author: Paul-Antwerp

Nowhere in my statement can one find anything about fire, while your post only addresses fire. So, you are asking me to prove a point that I did not even put forward.

I was not referring to your statements, but to David''s questions about cut grade, a science or not.
Of course, diamond grading is a science.
But ... about the stone I''ve linked, every Pricescope prosumer would say it lacks of fire, but nobody can prove it using science.
(And probably they can''t prove it with their experience, because most of the 32.5 crown they saw came with a much deeper pavilion, and that is what kills the fire.)
If you ask on pricescope how the diamond is performing, prosumers will answer it''s near ideal because of the slightly too shallow crown.
Why?
I don''t understand what potential difference there is.

Serg, I just understand that the diamond industry won''t invest in research, because they know yield will be less.
And if they invest, it''s just to show the consumer how steep/deep diamonds are attractive (GIA).

AGS did serious work, but most of the people here tend to believe that shallow crowns are not as good, even if AGS says it''s ideal.
The 34.5 myth still survives...

 

[Regular Guy]

Date: 3/11/2010 9:11:14 AM
Author: Serg


Most publications were just descriptions ( without any real hypotheses, testing and proof)
Science standards in Diamond industry is very very low because Diamond industry are not interesting to pay for science work. Science is not part Diamond industry.
Again my opinion what Science methods are enemy for most( may be for all)current Diamond business models.
99.9% professionals in diamond industry do not like science approach or can not understand what it is.( if we speak about CutStudy, Grading,..etc)
Science is very expensive Toy for diamond industry yet.

You might consider what the sources of motivation would be to get serious.

For this guy, pictured...

he needs diamonds to live.

Otherwise...they are not needed to support bridges, the precision of their cut probably doesn''t determine whether motors will work, etc.

Maybe rich people will be able to afford especially nice ones, and less rich ones will appreciate and value a diamond cut to attractive proportions...

But...what would otherwise be the motivation to drive high intensity rigor in evaluating one cut type versus another...

 

[diagem]

Date: 3/11/2010 10:23:53 AM
Author: QueenMum

Date: 3/11/2010 9:44:14 AM
Author: Paul-Antwerp

Nowhere in my statement can one find anything about fire, while your post only addresses fire. So, you are asking me to prove a point that I did not even put forward.

I was not referring to your statements, but to David''s questions about cut grade, a science or not.
Of course, diamond grading is a science.
But ... about the stone I''ve linked, every Pricescope prosumer would say it lacks of fire, but nobody can prove it using science.
(And probably they can''t prove it with their experience, because most of the 32.5 crown they saw came with a much deeper pavilion, and that is what kills the fire.)
If you ask on pricescope how the diamond is performing, prosumers will answer it''s near ideal because of the slightly too shallow crown.
Why?
I don''t understand what potential difference there is.

Serg, I just understand that the diamond industry won''t invest in research, because they know yield will be less.
And if they invest, it''s just to show the consumer how steep/deep diamonds are attractive (GIA).

AGS did serious work, but most of the people here tend to believe that shallow crowns are not as good, even if AGS says it''s ideal.
The 34.5 myth still survives...

Thats not really the issue..., I believe the issue has more to do with the lack of knowledge..., the Diamond industry is just (extremely slowly) beginning to face new technological advancement..., its still in its beginnings but with no doubt will grow as a natural path if the results prove themselves.

We are talking about an extremely primitive industry that has handled itself in this fashion for Centuries.

 

[Paul-Antwerp]

This is frustrating.

RD is putting me on trial (kind-of), because he disagrees with my statement:

"GIA''s and AGS''s cut-grade, ASET, IS and HCA are indeed valid techniques, some of them vetted by science, to judge potential brightness most often of a round brilliant only."

Now, after a lot of word-twisting, everybody is giving opinions aside from the original topic.

Question: If going back to my original question, can anybody disagree? If not, can we agree that this is an undisputable basis?

Live long,