Grading of Ideal cut diamonds, a better way.

[Cehrabehra]

Date: 4/30/2007 8:47:54 PM
Author: Garry H (Cut Nut)

Why does diamond – the ultimate luxury product – loose out so badly to “other luxury goods”? It is because other luxury industries (expensive cars, high fashion, yachts, etc,) practice technical novelty, fashionable brands and customization, while diamonds evolved into a very traditional business with little innovation. How did it happen?

Since the early 1900’s professionals worked with cuts to stimulate consumer demand by offering different diamond shapes and by working to improve the proportions of the most popular shape, the round brilliant.

The very successful “Diamond is Forever” campaign was the first major step towards stopping diamond Cut evolution. It was launched by De Beers in the 1940’s and created a mass diamond market, especially for diamond engagement rings. However, this mass marketing ideology did little to differentiate between diamonds, so the main market differences became those of nature: clarity, colour and size.

Even still, here and now, Garry - you see FIC, TIC, and BIC and think oh - no extremes for me! perfection must be in the *balance* between the two!

In the fire size poll I did a couple days ago, over 50% said they preferred medium sized fire like that of a round brilliant and this was no surprise. only 14% (as of now) have said they like pinfire such as found in radiant and princess and yet the princess is wildly popular - even here. Chunky omc/oec fire got a whopping 30% vote and we all know that omc/oec make up a far lesser % of what even the people here buy. They go for the rounds because they're a) THE BEST and b) STRONG AND SYMMETRICAL.

How much you wanna bet the first person who can make an optically symmetrical, optically powerful, high crowned, pretty from 180*, chunky faceted stone is going to make a mint?

ETA just to clarify - doesn't have to be a cushion shape - in fact if you take what we know (or rather what YOU know) about rounds and just fiddle with it, that would be really easy and you'd (relatively quickly) reinvent the OEC maybe calle it the MEC (modern european cut lol - or OEB old european brilliant) omg it could certainly be the next big thing with not a whole lot of effort. If people could buy oec stones that were optically superior... it wouldn't take ALL of the market from ACA for example - but if WF had two distinct flavors - vanilla and chocolate - to offer, wouldn't that be fantastic?? Deal with cushions later, they're PITAs lol

 

[oldminer]

Here are three of the new style diamond reports we are beginning to offer to dealers and the public. I think the trade may have a very hard time with the DFS grade as it presently exists since it hits pretty hard for the combinations of over depth and thick girdle on two stones and graded them 5, the lowest DFS score. They are truly lumpoy diamonds. You can also see that the stone with a more moderate girdle and less over depth scored a 2 on DFS.

I have a feeling that consumers would want to know this information more than diamond sellers.

Please also see that all three diamonds had Excellent Light Behavior grades. Two were EX+, and one was EX.

The reason for posting these was to demonstrate a system which allows high poerformance cuts of any configuration to be described. While the outcome of the DFS may not be palatable to sellers, I think buyers are constantly asking for results that meet this approach.

 

[oldminer]

#2

 

[oldminer]

#3

 

[He Scores]

Gary wrote:

It is good to aim for an ideal
but bad to proclaim achievement of ideal


I like this Gary....you don''t mind if I use it do you? Like I had exlained, my scoring system is based on the bulk of the Tolkowsky theoretical with minor adjustments.


Knowing cutting, it is highly unlikely that anyone would achieve a perfect score of 1000 on my scoring scale....but like you say, it''s good to aim for it. Cutters of fine makes do it every day. My sytem doesn''t include Rubrics that segregate one stone from another...it simply applies a mathematical derived score to it. Some people may call a 900 excellent, some may call an 850 excellent, but one things for certain...few will look at a 900+ stone and say it''s a bad cut or that one thats 20% lower in score will look better, like you see in the Rubric style systems used at the labs today.


Bill Bray
Diamond Cutter

 

[He Scores]

Since we have most of the PS cut geeks here, will anyone of you take me as your date to Peter''s BBQ? I was sort of handed a backhanded invitation after last year,s and I don''t want to invite myself this year.

My invitation must have gotten lost in the mail.

Bill

 

[oldminer]

"Cutters of fine makes do it every day. My sytem doesn''t include Rubrics that segregate one stone from another"

You say you don''t segregate one stone from the other, but your system makes 1000 distinctions instead of the fewer ones I propose. The engineer types will want a stone that scores no less than a high number, like 920, no matter what the visual choices might be. Others may understand that a 920 does not necessarily have more eye appeal than an 842. While you might see a difference, they probably would not. People might prefer the 842 to the 920 more often than not. No one knows. I do believe that you can readily prove that a 920 is better crafted than a 842. I am attempting to make the same sort of distinctions with the DFS but only stick to features which are readily detected and understood. I don''t know if the consumer want the in depth variety of grade you propose, or a less complex version such as I propose. My experience has been that systems need to be exp0lained to people and a simple system is a lot less problematic to explain to consumers. Both systems are honest, but they are very different in the level of their respective technical approaches.

The Bray Score has the positive aspect of being factual and repeatable. It is a direct reference to craftsmanship. No doubt about it.

Could the BrayScore eliminate the reference point of TOlkowsky and only use symmetry and polish measures without reference to Tolkowsky? By doing that, it would be more useful for any shape instead of just for rounds.

 

[He Scores]

Re:Could the BrayScore eliminate the reference point of TOlkowsky and only use symmetry and polish measures without reference to Tolkowsky? By doing that, it would be more useful for any shape instead of just for rounds.
David S. Atlas

Dave,
The only thing "Tolkowsky" that BrayScore judges on is the top and bottom crown main angle measurements. More so than just a strict model, my scoring system is based on the criteria that a cutter either consciously or unconsciously makes when he/she makes a facet.

How does a cutter know when he is making a facet on a diamond, when that facet is considered properly made? There are three or four factors that have to be considered for each and every facet and they are measurable with today''s machines. My scoring system takes these factors and scores them for accuracy. Angles as put out by Tolkowsky are only one of the elements. The other elements are based on basic mathematics...(dividing a pie into equal parts) and these really can''t be argued.

Since these factors are inherently subscribed to by all cutters making all shapes, then yes a BrayScore could be developed to encompass the work done on a fancy shape.

I''ve tested BrayScore on retail customers deciding on which diamond to buy and have found it to be a very informative, easy to understand piece of information on which to help them make a buying decision.

As far as including finish in ANY cut grading, I am opposed to that from the stand point that finish is sometimes beyond
the control of the cutter. Here again, I am aluding to "how well the stone is cut?" equalling, "how well did the cutter do his job?". While I agree that it should be noted on any and all reports, it should not influence the cut grade, especially since few people in the trade can pick up finish marks with a loupe. Finish quality should be in line with clarity grading and done with ten power. When cutter''s have to go with IP systems that view finish under 100X magnification like is being done in some shops today, it''s over-kill. What''s next? Electron microcopes to examine internal flaws....just for the sake of examining internal flaws because we can?

Bill Bray
Diamond Cutter

 

[adamasgem]

Date: 5/1/2007 9:59:22 AM
Author: He Scores


Since we have most of the PS cut geeks here, will anyone of you take me as your date to Peter''s BBQ? I was sort of handed a backhanded invitation after last year,s and I don''t want to invite myself this year.

My invitation must have gotten lost in the mail.

Bill

You''re in.. Peter hasn''t sent them out yet...
Marty

 

[strmrdr]

Date: 5/1/2007 8:57:44 AM
Author: oldminer
#3

need lgf% on them.

 

[He Scores]

RE: 4. With round diamonds only, we can consider crown angle since it ought to be very consistent over the entire diamond. Too shallow a crown angle encourages breakage. No real fault happens with steeper angles. With fancy shapes, we expect crown angles to be different all around the diamond with the rounded shapes and differ from side to side on the rectangular shapes. The only discount is for shallowness, not steepness and then only for rounds.


Dave,
Just a quick point. Steep crown angles have a major fault. If you have the same diameter stone and the same size table but the one stone has a two degree steeper angle, what do you think happens? Anyone? Draw it out on paper and you''ll see.

A: The girdle is eliminated and the stone becomes a smaller diameter.

Facet angle is one of the elements in cutting and cannot be ignored. I could comment to about the facet angle difference in fancies too, but I don''t want to seem to be picking your system apart.


Bill Bray
Diamond Cutter

 

[Cehrabehra]

Date: 5/1/2007 4:26:23 PM
Author: He Scores


RE: 4. With round diamonds only, we can consider crown angle since it ought to be very consistent over the entire diamond. Too shallow a crown angle encourages breakage. No real fault happens with steeper angles. With fancy shapes, we expect crown angles to be different all around the diamond with the rounded shapes and differ from side to side on the rectangular shapes. The only discount is for shallowness, not steepness and then only for rounds.


Dave,
Just a quick point. Steep crown angles have a major fault. If you have the same diameter stone and the same size table but the one stone has a two degree steeper angle, what do you think happens? Anyone? Draw it out on paper and you''ll see.

A: The girdle is eliminated and the stone becomes a smaller diameter.

Facet angle is one of the elements in cutting and cannot be ignored. I could comment to about the facet angle difference in fancies too, but I don''t want to seem to be picking your system apart.


Bill Bray
Diamond Cutter

I dont'' see how this makes sense... why wouldn''t having an increased depth and increased crown height accommodate it?

 

[He Scores]

Sarah,
Lets see how can I help you understand this?

Take a profile line drawing of an ideal cut diamond. Take a ruler and protractor and increase the the angle of the top main and see where the bottom of the ruler goes. Through the girdle no?

This was one of the misconceptions when "digging" upper halves was discussed...that increasing the crown height ADDS weight to the stone.

You can''t add weight by removing material. If you raise the crown angles on an identical stone, you''ll decrease the diameter of the stone. Diameter in diamond cutting is synonomous with weight.

I hope this helps.

Bill Bray
Diamond Cutter

 

[strmrdr]

Date: 5/1/2007 8:06:51 PM
Author: He Scores
If you raise the crown angles on an identical stone, you'll decrease the diameter of the stone.

Bill Bray
Diamond Cutter

only if you keep the weight the same.
a higher crown angle with the same size table == a heavier diamond for any given diameter.
And since the diameter of the diamond is set by the rough the higher the crown the heavier the diamond unless the pavilion angle is reduced to match or the table % changed.

 

[He Scores]

RE: only if you keep the weight the same

That''s a pretty big if Strm....I hate to disagree with you but what you don''t seem to get here is that you need to remove material to raise the crown angles. When you remove material, you LOSE weight. You will end up with higher crown angles, less diameter, and less weight. It doesn''t matter if the crown percentage is increased. This is one of the problems of modelling, it doesn''t reflect the actuality of sculpting the stone on the wheel.

Trust me.

Bill Bray
Diamond Cutter

 

[strmrdr]

Date: 5/1/2007 9:17:58 PM
Author: He Scores

RE: only if you keep the weight the same

That's a pretty big if Strm....I hate to disagree with you but what you don't seem to get here is that you need to remove material to raise the crown angles. When you remove material, you LOSE weight. You will end up with higher crown angles, less diameter, and less weight. It doesn't matter if the crown percentage is increased. This is one of the problems of modelling, it doesn't reflect the actuality of sculpting the stone on the wheel.

Trust me.

Bill Bray
Diamond Cutter

I'm seeing the light we are talking about 2 different things, your talking rough weight retention and im talking finished stone weight.
I can see it if your cutting tops or some other forms of rough then a higher crown would equel lower diameter.
But if you cut the rough for the widest possible diameter and put the crown above the center line of the octahedron then I dont see it.

 

[He Scores]

Strm...you''re making this more difficult than it really is. Keep it simple.

Take two identical .50ct. ideal cut diamonds. Same everything.

You take one and raise the crown angles and you''ll lose weight and diameter in order to increase the crown angles.


Bill

 

[strmrdr]

ahah, a high crown bottom would push the girdle of the top stone up reducing its diameter so you would lose weight there too.
Am I getting what your saying now?

 

[He Scores]

RE: ahah, a high crown bottom would push the girdle of the top stone up reducing its diameter so you would lose weight there too.
Am I getting what your saying now?
................


You''re getting there.

You actually push the girdle to the bottom of the stone, and yes you will reduce the diameter.

I see the light bulb go on Strm....

 

[strmrdr]

Date: 5/1/2007 9:37:09 PM
Author: He Scores
Strm...you''re making this more difficult than it really is. Keep it simple.

Take two identical .50ct. ideal cut diamonds. Same everything.

You take one and raise the crown angles and you''ll lose weight and diameter in order to increase the crown angles.


Bill

but diamonds are not cut that way, the diameter is set first by bruting and blocking.

 

[Garry H (Cut Nut)]

Back to topic

Date: 5/1/2007 8:56:30 AM
Author: oldminer
Here are three of the new style diamond reports we are beginning to offer to dealers and the public. I think the trade may have a very hard time with the DFS grade as it presently exists since it hits pretty hard for the combinations of over depth and thick girdle on two stones and graded them 5, the lowest DFS score. They are truly lumpoy diamonds. You can also see that the stone with a more moderate girdle and less over depth scored a 2 on DFS.

I have a feeling that consumers would want to know this information more than diamond sellers.

Please also see that all three diamonds had Excellent Light Behavior grades. Two were EX+, and one was EX.

The reason for posting these was to demonstrate a system which allows high poerformance cuts of any configuration to be described. While the outcome of the DFS may not be palatable to sellers, I think buyers are constantly asking for results that meet this approach.

It is an interesting format Dave
I sometimes feel for the diamond buying public - we smack them around the ears with such a huge amount of information.
Even when an atempt is made, like yours, it is still confusing.

 

[He Scores]

No....but we''re changing existing angles.

We''re re-cutting.

I''m going to bed....goo night.

 

[Richard Sherwood]

Date: 4/30/2007 9:01:06 PM
Author: He Scores

Read my lips. There is no such thing as the best performing diamond. Just like no woman is the most beautiful, or a place in nature is the most beautiful, nor a piece of artwork, or a piece of jewelry, or a house. THE MOST BEAUTIFUL OF ANYTHING DOES NOT EXIST.

It can exist....just as a perfectly cut diamond CAN''T exist.

Bill Bray
Diamond Cutter

No truer words have every been spoken.

People keep want to keep quantifying diamonds. It is not possible. There is an aspect to diamonds which is akin to works or art. I have seen Old European Cut diamonds which defied all the rules and out performed modern Ideal Cut stones.

The numbers people would greatly discount these stones, while the connoisseurs who appreciate beauty would give these stones a premium.

The eye is the end judge of beauty. Those who have confidence in their eyes to judge beauty will alway outperform those who judge solely based on the numbers.

 

[strmrdr]

Date: 5/1/2007 9:50:25 PM
Author: He Scores
No....but we''re changing existing angles.

We''re re-cutting.

I''m going to bed....goo night.

night....
ok recutting changes things.....
my question is why someone would want to re-cut a shallow crown into a steep one......

 

[strmrdr]

Date: 5/1/2007 9:59:19 PM
Author: Richard Sherwood

Date: 4/30/2007 9:01:06 PM
Author: He Scores

Read my lips. There is no such thing as the best performing diamond. Just like no woman is the most beautiful, or a place in nature is the most beautiful, nor a piece of artwork, or a piece of jewelry, or a house. THE MOST BEAUTIFUL OF ANYTHING DOES NOT EXIST.

It can exist....just as a perfectly cut diamond CAN''T exist.

Bill Bray
Diamond Cutter

No truer words have every been spoken.

People keep want to keep quantifying diamonds. It is not possible. There is an aspect to diamonds which is akin to works or art. I have seen Old European Cut diamonds which defied all the rules and out performed modern Ideal Cut stones.

The numbers people would greatly discount these stones, while the connoisseurs who appreciate beauty would give these stones a premium.

The eye is the end judge of beauty. Those who have confidence in their eyes to judge beauty will alway outperform those who judge solely based on the numbers.

ah but if you find a stone you love the numbers will let you find a another simular one.
Which is the concept of ideal diamonds....

 

[Garry H (Cut Nut)]

Date: 5/1/2007 9:59:19 PM
Author: Richard Sherwood

Date: 4/30/2007 9:01:06 PM
Author: He Scores

Just like no woman is the most beautiful,
,Bill Bray
Diamond Cutter

The eye is the end judge of beauty. Those who have confidence in their eyes to judge beauty will alway outperform those who judge solely based on the numbers.

Off topic, but could not resist
The numbers do nothing for me either - but how do blind people judge?

 

[Richard Sherwood]

Date: 5/1/2007 10:41:04 PM
Author: Garry H (Cut Nut)
Off topic, but could not resist
The numbers do nothing for me either - but how do blind people judge?

True, I see your point. Numbers have their place in the overall scheme of things. They''re great for predicting performance. Sometimes they don''t allow for the exceptions, but I guess this is the minority, eh?

 

[Paul-Antwerp]

Back to topic.

Indeed an interesting format, Dave.

However, I definitely do not like the way in which you originally post questions as a stimulus for the exchange of ideas, and then suddenly surprise us with a finished format. I personally have given some positive remarks on your original questions, but this absolutely does not mean that I endorse the finished format that you are bringing up now. Especially since it is absolutely unclear and highly doubtable that you have made adaptations where we suggested these after the first questions.

I am making a big case here if you are going to use this size-measure on fancy shapes. First, depth is in this case not a size-measure, and should not be used in that way. Second, without any historical benchmark (like Tolkowsky in rounds), you have no idea of the reasonable size of a fancy-shape.

As for the score on light behavior, if I do not know what this score is based upon, I cannot judge its validity. I do however disagree that great face-up-performance automatically means the same when tilted.

Live long,

 

[oldminer]

Paul: Sorry if you don''t like the style of my posting. I post something of interest when the thought occurs to me. I am not a eveil genius spending my time thinking how I am going to promote my agenda or show I have a finished product. I jsut let the conversation flow and follow it. Once in a while I steer it a little to get it back on topic or respond to remarks made by others who intentionally or accidentally misconstrue what I was attempting to communicate. I want to educate, inform and stimulate discussion. If I have good ideas, I may succeed in influencing the long term outcome in a beneficial way, just like a teacher in school hopes to do for society. Its a fair goal.

I admit to sticking to subjects I am familiar with that I am also interested in. I just can''t help myself since I don''t want to post things that I don''t find challenging, or thought provoking. Before I type out a message, I try to discover a way to elicit many responses and lots of lurkers who come back over and over to read the thread. This is the must-have component for a site like Pricescope.

It is self serving for me to participate here as well as emotionally rewarding. Financial needs are met by increased business, which we always hope to obtain, but nothing directly by my voluntary participation here. I know a few folks have questioned Leonid about any direct relationship with me or my firms, but there is no hidden or other agreement. With time at a premiunm I need meaningful communication with consumers and the trade. No other diamond oriented website offers what Pricescope does in this regard, and that''s one of the main reasons I log on so frequently.

I hope this response leads to increased trust of my motivations. My main agenda is like yours. Make friends and grow my small business.