Low LGF%? Need advice on this stone

[michaelgem]

echelon6 says:

I read the article you linked to a while back last night and I didn''t find much explanation on why the LGF sweet spot is at 77.5% except that you mentioned that several groups and experts all agree?

I was thinking exactly on the same line as the Everest - Himalayan example. The ideal LGF answer being the arithmetic midpoint only applies if performance varies linearly with LGF. But as with many things, linear relationships are somewhat rare in real life, so at the moment without further explanation, the LGF midpoint theory doesn''t seem logical to me.

Could you please elaborate?

echelon6,

Strm’s answer to Pyramid is right on. when he says:

“I get into arguments with some of the experts on that all the time. I think a lot of consumers can see the differences, I can, but some can’t.
The question becomes when do the differences matter.
That is the heart of the issue. There is no question that different lgf% give a different look The argument is at what point does it become a performance issue rather than a personality difference. Strmrdr

From my previous post you know that I am not saying that the sweet spot center of 77% in pavilion half length is any better in GIA’s opinion or mine than any other % within our respective sweet spot ranges. What I personally like best is the larger flashes of sparkle and fire reminiscent of Old European cuts that come from larger mains closer to 76%.

As the pavilion half length exceeds 80% the mains get too thin to provide large flash sparkle and fire, but their scintillation is great in jewelry store lighting, which is likely why they are cut that way. So my opinion and that of the cutters of optically symmetric Ideals that I spoke to seem to converge in the vicinity of 77%.

I thought it was another fairly remarkable accordance when I learned that GIA had hard limits of 70% to 85% on LGF%, which gave the same sweet spot center.

In a conversation with Al Gilbertson, I learned that their statistical analysis of the paired comparison testing revealed an answer to Strm’s question of when does lgf% become a beauty/performance negative rather than just a personality/ pattern difference. Under 70% GIA found that the halves were too small and those stones were seen as deficient in sparkle/scintillation. Exceeding 85% caused the pattern to be seen as too “splintery”.

My detailed explanation for why I choose 77% as the sweet spot center of Ideal LGF% is too long for here, but it contains supporting diamond photography and DiamCalc images. I would enjoy hearing what everyone thought of it.

My conclusion was that the best balance between the areas of the main reflections with their large flash sparkle and fire, and the area of the halves, which provides more sparkle/scintillation is obtained with a 75% to 80% length of the pavilion halves.

In deference to Wink I do find larger main, well cut Old Europeans with their glorious, large flashes of fire and sparkle are in a beauty class of their own. Diamond cuts with too long halves with too thin mains lack this key component of the Essence of the Ideal.

Ideal regards,

Michael

 

[WorkingHardforSmallRewards]

Hey guys/wink, I just thought you might have overlooked this, I found it interesting:

Date: 7/19/2007 1:47:26 PM
Author: JohnQuixote

Michael decided to use AGS0 and AGS1 grades in his chart... if you use the 2006 cutting guidelines for AGS0 only... the center changes back toward Tolk.

Date: 7/19/2007 12:30:57 PM
Author: Wink

One reason may well be that many of us do not agree that 34/41 is in the center of the sweet spot. I do not, Paul does not, John Quixote does not, Brian does not, Bill Bray does not and AGS does not.


Wink

Date: 7/18/2007 11:16:32 AM
Author: Paul-Antwerp
Michael,


The concept of a 'sweet spot' being in the center of a lab's top-range is for me contrary to the original article of Bruce Harding, where top-performers are always close to an area where performance suddenly drops.


Is there any proof that Mount Everest is at the center of the Himalaya-range?


Live long,

 

[echelon6]

Date: 7/19/2007 11:01:26 PM
Author: michaelgem

My conclusion was that the best balance between the areas of the main reflections with their large flash sparkle and fire, and the area of the halves, which provides more sparkle/scintillation is obtained with a 75% to 80% length of the pavilion halves.

Too bad the stone I''m considering is RIGHT AT 74%

Is there some sort of cliff in performance at the limits of the plateau range of 75-80?

 

[pyramid]

ech

I think as consumers we are right in the middle here of a politics debate. I have the 34/41 diamond and I am feeling uncomfortable too in the way you are feeling about buying. What we must not forget is that Brian, Wink, Paul are selling diamonds with lower pavillion angles and in the case of the one you are speaking about a tiny bit lower LGF. Jonathan who I have dealt with has diamonds in the higher crown and pavillion angles as well as lower pavillion angle diamonds.

At this moment in time I really wish I had waited to buy after all this was ironed out but then I think it will be ongoing because we are in the middle of a competition struggle to get consumers. As Wink has pointed out though this may do more to scare all consumers away.

Ech I can see from your postings that you are more educated than I am by far with mathematics or engineering and I am sure you already know this. Although the people are not enemys of each other they are coming from two sides apart from the selling angle, there is Serg (very brilliant person, scientist), Jonathan (Gemmologist who has been dedicated here for years, I have seen him on diamond forums since 1998, Michaelgem (Research Scientist, Author) and then we have Brian (Master Cutter), Paul (Cutter), HeScores (Cutter, Inventor of BrayScore which takes his name), Wink (Gemmologist, long time business owner).

Although Jonathan is reassuring me when I ask questions, and I know he is honest and upright, the consumer is left with a feeling of what am I in the middle of here? Michaelgem said he has great respect for Brian, Paul, Cutters, he is a friend of Wink too. So they are all discussing these topics from different sides but OPPOSITE sides for a consumer to be able to come to an understanding about which diamond to choose.

Jonathan said something we have to think off when buying a diamond which 99% of the population will know nothing about, he said "there is critical examination and practical examination", other Consumers have said this is nano specs, Jonathan has called it minutia from the very first I asked him about pavillion angles. Sometimes it may be better I think if these type of discussions took place on their trade site Polygon, although I don't know if they have discussions of this type or what there. It is good that the consumer is seeing things so open if they are thinking of buying in the future and some things change with time, but the consumer buying now is left worried about their decision, wishing they had not bought the diamond yet, or in Ech's case needs to buy now for a proposed engagement but unsure what to buy.

For instance with my diamond, I can return it to Jonathan, he is not against this, but then if I do, what do I do, if I buy from say Whiteflash, Wink, I have the same dilemma, the Cutters are in agreement their specs are great but I am left thinking the diamond I returned is great by Serg, Michaelgem and Jonathan's arguments.

The parties here say they are not on opposite sides of the fence, but they are, the Cutters/JohnQuixote are saying it is safer to buy in their specs than 41 pavillion angle, now although Jonathan and Michaelgem do not believe this it is Jonathan on his own who is being left on the other side of the fence in regards to selling his products, although he does have both types. It seems in a way as though he is being ganged up upon by the vendors on the board because Michaelgem and Serg are not selling diamonds.

 

[pyramid]

I just wanted to add, I had thought stick with Whiteflash or Wink and that is the safest specs for a consumer to buy from, but why are they saying this, because all the diamonds they are selling have already got the AGS0 light return which mine has, I have been told mine is okay because it got this and not an AGS1 or 2 which diamonds could have got in the other specs. I know consumers not buying AGS0 certificates would see that as helpful but these vendors ARE selling AGS0. However, I have also thought there is an opposite side to this safety, the fact that although Jonathan is a vendor in the same way as they are, there are two unbiased opinions on the side of the steeper/deeper specs those of Michaelgem and Serg who are not selling diamonds.

I am afraid it makes no difference to a consumer who has spend a great deal of money on a diamond to be told her one got top grade but the type of parmeters it is cut too may not have got this grade. It leaves you feeling it is in a way more faulty in that it is near to the specs of those diamonds who may not get this grade. Now there is unbiased opinions here saying that Steeper Deeper diamonds would probably get AGS0 so who do we believe.

Yes to other consumers and I would be the first to think this too, this does not matter, do you like the look of the diamond etc but this does not help someone who is paying thousands of dollars and is hearing from experts different views, if it was two doctors debating something would you take a laypersons view? No. Yes it may be minutia or nano specs but consumers want to know what is better. At the moment I feel like returning my diamond and buying none.

 

[Garry H (Cut Nut)]

Date: 7/19/2007 11:39:06 PM
Author: WorkingHardforSmallRewards
Hey guys/wink, I just thought you might have overlooked this, I found it interesting:

Date: 7/19/2007 1:47:26 PM
Author: JohnQuixote

Michael decided to use AGS0 and AGS1 grades in his chart... if you use the 2006 cutting guidelines for AGS0 only... the center changes back toward Tolk.

Date: 7/19/2007 12:30:57 PM
Author: Wink

One reason may well be that many of us do not agree that 34/41 is in the center of the sweet spot. I do not, Paul does not, John Quixote does not, Brian does not, Bill Bray does not and AGS does not.


Wink

Date: 7/18/2007 11:16:32 AM
Author: Paul-Antwerp
Michael,


The concept of a ''sweet spot'' being in the center of a lab''s top-range is for me contrary to the original article of Bruce Harding, where top-performers are always close to an area where performance suddenly drops.


Is there any proof that Mount Everest is at the center of the Himalaya-range?


Live long,

For the record I have absolutely no evidence (from quite some experiance) that anyone, including all of you other nerds, could tell the difference between Tolkowsky and 34 41.

34.5-34= 0.5degrees and on the natural slope (1P=5C) that means the pavilion angle that goes with 34 is 40.85 - anyone game to bet their house they can see the difference? (or their Porsche?

)

And if 41 P has a natural equivalent to Tolkowsky then it is 41-40.75 = 0.15 X 5 = 0.75 subtracted from 34 = 33.25........ie the correct crown angle for Tolkowsky for a 41 pavilion = 33.25.

You''all is splittin hairs that are a waste of time.

Who says there is a center point?


If you are guilty Michael, please put $10 in the box and say 50 haiil Mary''s

And who cares?

 

[Serg]

Date: 7/20/2007 7:23:40 AM
Author: Garry H (Cut Nut)

Date: 7/19/2007 11:39:06 PM
Author: WorkingHardforSmallRewards
Hey guys/wink, I just thought you might have overlooked this, I found it interesting:

Date: 7/19/2007 1:47:26 PM
Author: JohnQuixote

Michael decided to use AGS0 and AGS1 grades in his chart... if you use the 2006 cutting guidelines for AGS0 only... the center changes back toward Tolk.

Date: 7/19/2007 12:30:57 PM
Author: Wink

One reason may well be that many of us do not agree that 34/41 is in the center of the sweet spot. I do not, Paul does not, John Quixote does not, Brian does not, Bill Bray does not and AGS does not.


Wink

Date: 7/18/2007 11:16:32 AM
Author: Paul-Antwerp
Michael,


The concept of a ''sweet spot'' being in the center of a lab''s top-range is for me contrary to the original article of Bruce Harding, where top-performers are always close to an area where performance suddenly drops.


Is there any proof that Mount Everest is at the center of the Himalaya-range?


Live long,

For the record I have absolutely no evidence (from quite some experiance) that anyone, including all of you other nerds, could tell the difference between Tolkowsky and 34 41.

34.5-34= 0.5degrees and on the natural slope (1P=5C) that means the pavilion angle that goes with 34 is 40.85 - anyone game to bet their house they can see the difference? (or their Porsche?

)

And if 41 P has a natural equivalent to Tolkowsky then it is 41-40.75 = 0.15 X 5 = 0.75 subtracted from 34 = 33.25........ie the correct crown angle for Tolkowsky for a 41 pavilion = 33.25.

You''all is splittin hairs that are a waste of time.

Who says there is a center point?


If you are guilty Michael, please put $10 in the box and say 50 haiil Mary''s

And who cares?

Garry,
Such type proof is not valid.

You can easy find difference between P42C29 and Tolkowsky. If you can see difference here, Why you can not see difference between 41/34 and Tolkowsky?( May be you can not, I can not, but B.G. can. It is question of training and goal)
When could you see difference between Tokowsky and (P40.75+x)C( 34.5-5x)? What is magic value for x ?

 

[Ellen]

Date: 7/20/2007 7:21:28 AM
Author: Pyramid
I just wanted to add, I had thought stick with Whiteflash or Wink and that is the safest specs for a consumer to buy from, but why are they saying this, because all the diamonds they are selling have already got the AGS0 light return which mine has, I have been told mine is okay because it got this and not an AGS1 or 2 which diamonds could have got in the other specs. I know consumers not buying AGS0 certificates would see that as helpful but these vendors ARE selling AGS0. However, I have also thought there is an opposite side to this safety, the fact that although Jonathan is a vendor in the same way as they are, there are two unbiased opinions on the side of the steeper/deeper specs those of Michaelgem and Serg who are not selling diamonds.

I am afraid it makes no difference to a consumer who has spend a great deal of money on a diamond to be told her one got top grade but the type of parmeters it is cut too may not have got this grade. It leaves you feeling it is in a way more faulty in that it is near to the specs of those diamonds who may not get this grade. Now there is unbiased opinions here saying that Steeper Deeper diamonds would probably get AGS0 so who do we believe.

Yes to other consumers and I would be the first to think this too, this does not matter, do you like the look of the diamond etc but this does not help someone who is paying thousands of dollars and is hearing from experts different views, if it was two doctors debating something would you take a laypersons view? No. Yes it may be minutia or nano specs but consumers want to know what is better. At the moment I feel like returning my diamond and buying none.

THIS is what I was affraid of.

Reading all this CAN begin to take the real beauty of a diamond away. I quit reading what all the experts had to say for a long time, for this very reason. I loved my stone, which is stunning thankyouverymuch, and I wasn''t going to have someone who hadn''t seen it persuade me otherwise. I can read it now, just for the heck of it, but I pay no mind when it comes to my diamond, because it''s beautiful, and brings me much joy. You could NOT pry it off my finger, even for a bigger size, which I wouldn''t mind having now.

Pyramid, please, quit reading this stuff and enjoy your diamond, which I''m sure is stunning.

 

[Garry H (Cut Nut)]

It is not at 0.15 Sergey. Maybe Brian can pick 41.2 32.8?

And at 42 29 the difference would be that many uninfluenced consumers would like it in Pepsi taste tests.

Date: 7/20/2007 7:34:39 AM
Author: Serg
Garry,
Such type proof is not valid.

You can easy find difference between P42C29 and Tolkowsky. If you can see difference here, Why you can not see difference between 41/34 and Tolkowsky?( May be you can not, I can not, but B.G. can. It is question of training and goal)
When could you see difference between Tokowsky and (P40.75+x)C( 34.5-5x)? What is magic value for x ?

 

[WinkHPD]

Date: 7/20/2007 4:47:22 AM
Author: echelon6

Date: 7/19/2007 11:01:26 PM

Author: michaelgem

My conclusion was that the best balance between the areas of the main reflections with their large flash sparkle and fire, and the area of the halves, which provides more sparkle/scintillation is obtained with a 75% to 80% length of the pavilion halves.

Too bad the stone I''m considering is RIGHT AT 74%

Is there some sort of cliff in performance at the limits of the plateau range of 75-80?

NO NO NO NO NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

There is a taste difference between liking the larger more cohesive flashes of light and dispersion, and liking the smaller more shattered look of tinier flashes of light and dispersion.

I feel I have failed miserably to explain this if after days of posting and reading that this point has not been made. Michaelgem''s arbitrary decision does not a consensus make and both AGS and GIA have given a much larger range. His narrow range truly is in the middle of the acceptable range, but it is much narrower than the range allowed by both GIA and AGS. There is nothing "wrong" with the length of LGF in the stone that you are looking at.

In fact at this point, the only thing wrong with the stone that you are considering is that you are not yet looking at it. Only your eyes will be able to answer your questions from here, the paper can not. In fact, the paper never could, it is designed only to tell you which candidates are worthy. From here your own eyes and your own taste must take over.

Wink

 

[pyramid]

Date: 7/20/2007 8:12:15 AM
Author: Ellen

Date: 7/20/2007 7:21:28 AM
Author: Pyramid
I just wanted to add, I had thought stick with Whiteflash or Wink and that is the safest specs for a consumer to buy from, but why are they saying this, because all the diamonds they are selling have already got the AGS0 light return which mine has, I have been told mine is okay because it got this and not an AGS1 or 2 which diamonds could have got in the other specs. I know consumers not buying AGS0 certificates would see that as helpful but these vendors ARE selling AGS0. However, I have also thought there is an opposite side to this safety, the fact that although Jonathan is a vendor in the same way as they are, there are two unbiased opinions on the side of the steeper/deeper specs those of Michaelgem and Serg who are not selling diamonds.

I am afraid it makes no difference to a consumer who has spend a great deal of money on a diamond to be told her one got top grade but the type of parmeters it is cut too may not have got this grade. It leaves you feeling it is in a way more faulty in that it is near to the specs of those diamonds who may not get this grade. Now there is unbiased opinions here saying that Steeper Deeper diamonds would probably get AGS0 so who do we believe.

Yes to other consumers and I would be the first to think this too, this does not matter, do you like the look of the diamond etc but this does not help someone who is paying thousands of dollars and is hearing from experts different views, if it was two doctors debating something would you take a laypersons view? No. Yes it may be minutia or nano specs but consumers want to know what is better. At the moment I feel like returning my diamond and buying none.

THIS is what I was affraid of.

Reading all this CAN begin to take the real beauty of a diamond away. I quit reading what all the experts had to say for a long time, for this very reason. I loved my stone, which is stunning thankyouverymuch, and I wasn''t going to have someone who hadn''t seen it persuade me otherwise. I can read it now, just for the heck of it, but I pay no mind when it comes to my diamond, because it''s beautiful, and brings me much joy. You could NOT pry it off my finger, even for a bigger size, which I wouldn''t mind having now.

Pyramid, please, quit reading this stuff and enjoy your diamond, which I''m sure is stunning.

Thanks Ellen, However I am feeling like returning it today, and going for the safer specs. Ofcourse, not that I think it is making me feel this way, but I think Wink has given me his Grumpy mood today now that he has gotten over it

, so I will read here but will not be writing. I do not mean to offend any of the Cutters, Gemmologists or Scientists but I just feel that the diamond I have picked is nearer to the steep/deep specs, well the deep pavillion when discussing ideal spec combinations, I also feel that when I have read advice to consumers before where it says their 34/41 is a shallow/deep combination, I do not know if this is a bad description, as in just to show its relation to Tokowsky or as in it is a deep stone. It is certainly not like those drawings you see around the net showing a shallow, an ideal cut and a deep cut, so why are the diamonds near Tolkowsky being described as this to consumers. I know that Storm here likes the 34/41 pavillion but I have seen him giving consumers advice and saying the stone is a shallow/deep or a okay/medium or a steep/shallow etc.

 

[WorkingHardforSmallRewards]

Date: 7/20/2007 8:21:16 AM
Author: Pyramid

Date: 7/20/2007 8:12:15 AM

Author: Ellen

Date: 7/20/2007 7:21:28 AM

Author: Pyramid

I just wanted to add, I had thought stick with Whiteflash or Wink and that is the safest specs for a consumer to buy from, but why are they saying this, because all the diamonds they are selling have already got the AGS0 light return which mine has, I have been told mine is okay because it got this and not an AGS1 or 2 which diamonds could have got in the other specs. I know consumers not buying AGS0 certificates would see that as helpful but these vendors ARE selling AGS0. However, I have also thought there is an opposite side to this safety, the fact that although Jonathan is a vendor in the same way as they are, there are two unbiased opinions on the side of the steeper/deeper specs those of Michaelgem and Serg who are not selling diamonds.


I am afraid it makes no difference to a consumer who has spend a great deal of money on a diamond to be told her one got top grade but the type of parmeters it is cut too may not have got this grade. It leaves you feeling it is in a way more faulty in that it is near to the specs of those diamonds who may not get this grade. Now there is unbiased opinions here saying that Steeper Deeper diamonds would probably get AGS0 so who do we believe.


Yes to other consumers and I would be the first to think this too, this does not matter, do you like the look of the diamond etc but this does not help someone who is paying thousands of dollars and is hearing from experts different views, if it was two doctors debating something would you take a laypersons view? No. Yes it may be minutia or nano specs but consumers want to know what is better. At the moment I feel like returning my diamond and buying none.

THIS is what I was affraid of.


Reading all this CAN begin to take the real beauty of a diamond away. I quit reading what all the experts had to say for a long time, for this very reason. I loved my stone, which is stunning thankyouverymuch, and I wasn''t going to have someone who hadn''t seen it persuade me otherwise. I can read it now, just for the heck of it, but I pay no mind when it comes to my diamond, because it''s beautiful, and brings me much joy. You could NOT pry it off my finger, even for a bigger size, which I wouldn''t mind having now.


Pyramid, please, quit reading this stuff and enjoy your diamond, which I''m sure is stunning.

Thanks Ellen, However I am feeling like returning it today, and going for the safer specs. Ofcourse, not that I think it is making me feel this way, but I think Wink has given me his Grumpy mood today now that he has gotten over it

, so I will read here but will not be writing. I do not mean to offend any of the Cutters, Gemmologists or Scientists but I just feel that the diamond I have picked is nearer to the steep/deep specs, well the deep pavillion when discussing ideal spec combinations, I also feel that when I have read advice to consumers before where it says their 34/41 is a shallow/deep combination, I do not know if this is a bad description, as in just to show its relation to Tokowsky or as in it is a deep stone. It is certainly not like those drawings you see around the net showing a shallow, an ideal cut and a deep cut, so why are the diamonds near Tolkowsky being described as this to consumers. I know that Storm here likes the 34/41 pavillion but I have seen him giving consumers advice and saying the stone is a shallow/deep or a okay/medium or a steep/shallow etc.

Just remember that there has been no evidence to support the idea that the center of any grade is better than any other grade. consider it like this, at a certain pavilion angle, certain crown angles cause for certain affects. Assuming tolk is at the center of AGS ideal what does that really mean? It means that at that particlar pa/ca combo you can make smaller crown angles and still be in the ideal range--Lets call that variance number x. You can then adjust the pavilion angle to be larger--lets call that variance number y. Or you can adjust the crown angles...so forth and so forth. But to be geometrically at the center means that the variance or overall distance from that point to a point that would not make the ideal cut is equal.
but what does it matter if x=y? those distances have absolutely no bearing on light performance.

Everybody agrees that the AGS Ideal plane is not a flat plateau.

Imagine if you are climbing a wall or mountain. When you finally hit the top of it and climb over and lay down on the "flat" top of the mountain, is the very center of the top of that mountain going to be the single highest point on the mountain? No, there may be a little plain or plateau region at the top but there will be rocks of varying size strewn about, maybe a real big one sitting over on the edge. You can safely say that the whole top "flat" region of the mountain is the top of the mountain right? You can tell because overall there is a general trend of down as you go left and right, a general trend of positive and negative slopes, but once you hit the top plateu of the mountain you can''t simply measure it off x=y, find the center and call that the highest point. You have to look at the particular terrain, where each rock is laid, which one is the biggest or if a couple of the biggest are equal size.

That is where you are at, you are at the top of the mountain. In a real analogy, if the biggest rock or one of those "tied for the biggest" rocks at the top of the mountain were placed right at the edge of the plateau, well eventually it might fall off. But you have a diamond. The angle is not going to change, which means that it, if it is in fact one of those tallest rocks, will always be there exactly as it is. Which means that the fact it is sitting closer to the edge of the top of the mountain, overlooking the valley, has absoluetly no bearing on its height in relation to a rock sitting closer to the center of the mountain. It just doesn''t matter at all, because it isn''t a continually positive or negative slope, it is only gradually and in general terms positive or negative which makes the whole discussion of centers at the top a really moot and pointless discussion when talking about actual light performance.

And I am going to be late to work so I am sorry if some of this is unclear and spelled poorly, im in a hurry!

 

[WinkHPD]

Date: 7/20/2007 7:21:28 AM
Author: Pyramid
I just wanted to add, I had thought stick with Whiteflash or Wink and that is the safest specs for a consumer to buy from, but why are they saying this, because all the diamonds they are selling have already got the AGS0 light return which mine has, I have been told mine is okay because it got this and not an AGS1 or 2 which diamonds could have got in the other specs. I know consumers not buying AGS0 certificates would see that as helpful but these vendors ARE selling AGS0. However, I have also thought there is an opposite side to this safety, the fact that although Jonathan is a vendor in the same way as they are, there are two unbiased opinions on the side of the steeper/deeper specs those of Michaelgem and Serg who are not selling diamonds.

We are saying "this" because we believe it to be true. However, if you read all of my posts, and there are many, you will find that I also sell beauty. I constantly attempt to say "buy the stone, not the paper".

I sell, in house, many beautiful diamonds that are NOT AGS 0. Why, because my clients can see them and love them the instant they are revealed to them from within the diamond paper. On line, it is YOU the client, who is demanding ever more tightening degrees of perfection. Several years ago I used to just say buy the stone, trust your vendor, this paper stuff does not mean anything to your eyes.

Then I became acquainted with the early H&A stones that were just beginning to come into the country instead of going to Japan. I even had lunch with, and did a favor for, Richard von Sternberg, who would contact me a couple of years later and spend a great deal of time educating me on the magnificence of EightStar, for which I became a vendor.

That began my path of learning the nuances of the cutting. I met Michael Cowing at an EightStar convention and we talked until close to 2 AM the night before he would give a presentation at the convention. Somewhere in there I met Pete Yantzer, it may actually have been at EightStar, I am not sure, and we became friends as well as associates. (Neither of us remember exactly when we met, but we are both sure we like each other!)

I tried to sell John Quixote a diamond long before he was John Quixote, but his then fiance chose another and soon Brian the Cutter was smart enough to snatch him away from the music world and into ours.

One day Paul Slegers said on another board that he was going to enter the fray and needed dealers. I contacted him and he added me to his itinerary when he came to the States, and true to his word his diamonds rivaled anything I had ever seen, including the EightStar, and I became his first vendor. Now he has several Stateside vendors, and has just had a large cash infusion in his business which will result in over two million dollars of new inventory by late November. I will be able to say I knew him when.

It has been a great and interesting journey for me, and for John, I can say this because we both talk regularly and have both talked about how amazing our lives have been and how they have been changed by the evolution in diamond cutting. I strove to sell ideal cuts when I opened my store in 1976, but most of my clients would not pay the ten to fifteen percent premium so I ended up selling some of the same old (expletive deleted) that the mall stores were selling just to pay my bills. Now over 90% of the diamonds I sell are AGS 0''s or 1''s, with an occasional stone of lower cut grade or graded by GIA but being worthy of AGS 0 or 1.

What is my point? My point is I do not say the things I say because I sell stones that match the things I say, I sell the stones I sell because they match the things I believe.

I LIKE THESE GEMS! THEY MAKE MY EYES AND MY HEART HAPPY!!!!!!!!!!!!!!!!!!!!!!!

I did not say in this thread or any other that I did not like your stone. I said it is on the edge of the area, which it is, for an AGS 0. I said this before I even knew we were talking about your stone. I did not even say that I would not sell such a stone, I would be happy to sell your stone, it is a beauty and you should quit doubting your eyes. Either they like the stone or they don''t, and that is YOUR choice and YOUR choice alone. Not mine nor any of the people who agree with me, nor any of the people who disagree with me. YOURS!

Do I have an agenda? Darn right! I need to sell gems to feed my wife, or go get a real job. I don''t want a real job, I want to sell incredibly beautiful diamonds and I want to continue learning what makes beauty just that smidgen beautifuler.

Thus it is said, thus it shall be, and so it is.

Wink

 

[pyramid]

Thanks Working Hard. I hope ;you were not late for your work. I understand exactly what you are saying and would be happy with that if I was buying an AGS1 and knew it. However I want as perfect a daimond as I can get and this is a mind clean thing for me, I have made up my mind today and will be contacting Jonathan that I do want to return the diamond. I am going to wait a few months or year or so before I buy another diamond. I just feel very very uncomfortable with the diamond I have. I am not saying in anyway someone else will feel like this, the diamond looks fine, although I have had a bit of a time really liking it because I was used to seeing diamonds with larger tables. I am not going to be persuaded into keeping it now because I know this is what I need to do. I know this plateau is all AGS0 diamonds but it is a mind clean thing for me, it is not about it being at the centre, I do not want it to be perfect as in the one that is better than the rest although Michaelgem has stated many times by centre he does not mean in anyway it is better. However I do want it to be one of the safer picks and I do trust people like Brian Gavin, Wink, Serg, Michaelgem etc and also Jonathan. If everyone was of the same opinion that all diamonds on the plateau as equal then fine, but they are not, no matter if it is minutia, Brian Gavin & other cutters have said about colour entrapment, I can say with my own eyes I do not see that at all. However this is one diamond and I want to buy one where I do not even have to think for one moment that it may be different from all the rest.

 

[pyramid]

Wink I know that you and others are saying what you believe in the same way Michaelgem and Jonathan are, Serg can in a way prove through his charts that what he is saying is true. I know you have to be in business to feed your wife, so does everyone in the whole world, that is why I put that second message that I was not against anyone, I put about Jonathan being ganged up upon but I was not meaning it in a sense of being bullied just that he was on an opposite side of the fence as well as the same side because he has diamonds with other specs. I have looked at his inventory and if I could get one with a shallower pavillion in my budget I would change to this no question, however there is not one there at the moment. There are some more expensive and less expensive just not what I am looking for.

I just think that in the same way you all have your own beliefs so does a customer and although this is minutia I am not comfortable buying any diamond at the moment until I can think about this more. I know that Jonathan has a lifetime trade up policy but at the moment I am uneasy with the diamond I have so I have made a decision to return it. Just a decision for me and not caused by anything you have said at all Wink, I know you have never said this diamond I have is in any way lesser infact you said it was okay because it got the AGS0 grade. I am not saying this is REALLY business politics to Ech and it is about a struggle to win the customer but that is how it looks from the consumers point of view and how you would probably have doubts about it too if you were the consumer, if you would not then maybe you are more trusting than I am.

 

[WinkHPD]

Date: 7/20/2007 6:23:20 AM
Author: Pyramid
Sometimes it may be better I think if these type of discussions took place on their trade site Polygon, although I don''t know if they have discussions of this type or what there.

LOL, if only you knew.

typical Polygon discussion.

First commenter. "I just lost a sale to one of those dirty rotten internet vendors."

Second commenter, "Shut up and learn to compete."

Third commenter, well, you get the picture. I do not believe that I have EVER seen a discussion on Polygon on the discussion channel that goes into any meaningful depth about what constitutes good cutting.

Contrary to popular Pricescope belief, the majority of the people buying diamonds today do not know nor care about anything but cut, color and price. Those who believe in cut are in a very minor minority, and those who sell color clarity and price do well, as evidenced by the success of sites like Dirt Cheap Diamonds. Mr. Schultz knew very well who his market was when he built that site. He sells a LOT MORE DIAMONDS than I ever will, it was brilliant marketing.

We only have these discussions here because YOU, the rare well educated consumer, or those who wish to be well educated, demand them. Believe me, it would be a LOT easier to just say, "Hey, do you trust me? Then buy what I tell you!"

It works in so many places, it just doesn''t work here. And those of us who are here are here because we absolutely love it that you want to know more, as it forces us to know more. Ten years ago I could not have discussed LGF with you, nor would I have cared about them. Now that I know more about them and how they affect the flavor of the diamond (notice I did not say quality) I can passionately discuss them and care. Thank you for making me learn!

Wink

 

[WinkHPD]

Date: 7/20/2007 9:38:55 AM
Author: Pyramid
I know you have never said this diamond I have is in any way lesser infact you said it was okay because it got the AGS0 grade.

Herein lies the problem with talking too much. You are right, I did say that.

Somehow I should have imparted that it would in fact still be okay even if it had gotten the AGS 1, 2 or 3 grade if it made your eyes happy. It does not require an AGS 0 to make your eyes happy. However, an AGS 0 really is something special, and the chances that you will see any difference (let alone significant) in this gem and the one you eventually choose if set side by side is slim.

YET! It IS important to YOU, thus IT IS IMPORTANT.

I commend you for following your heart and your eyes, and I wish you well in your search.

Wink

 

[pyramid]

Thanks Wink and I know you know this too but I would not be paying the same price for an AGS1,2 or 3 and that is partly my reason along with the mindclean. I know this diamond is AGS0 and so Jonathan is charging the correct price but in my mindclean and probably stupid way I am seeing it as near the other diamonds measurements and as I am onlly buying one I want to get it right. If it was a pair of jeans it wouldn''t matter so much because they would wear out and don''t cost much. I am not saying this to criticise you Wink in anyway or any of the vendors but most people are buying one diamond, whereas to all of you it is a diamond of many you are selling.

 

[michaelgem]

Date: 7/20/2007 8:16:30 AM
Author: Wink

style="WIDTH: 94.84%; HEIGHT: 153px">Date: 7/20/2007 4:47:22 AM
Author: echelon6

style="WIDTH: 97.99%; HEIGHT: 79px">Date: 7/19/2007 11:01:26 PM

Author: michaelgem
My conclusion was that the best balance between the areas of the main reflections with their large flash sparkle and fire, and the area of the halves, which provides more sparkle/scintillation is obtained with a 75% to 80% length of the pavilion halves.

Too bad the stone I''m considering is RIGHT AT 74%

Is there some sort of cliff in performance at the limits of the plateau range of 75-80?

NO NO NO NO NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

There is a taste difference between liking the larger more cohesive flashes of light and dispersion, and liking the smaller more shattered look of tinier flashes of light and dispersion.

I feel I have failed miserably to explain this if after days of posting and reading that this point has not been made. both AGS and GIA have given a much larger range. His narrow range truly is in the middle of the acceptable range, but it is much narrower than the range allowed by both GIA and AGS. There is nothing ''wrong'' with the length of LGF in the stone that you are looking at.

In fact at this point, the only thing wrong with the stone that you are considering is that you are not yet looking at it. Only your eyes will be able to answer your questions from here, the paper can not. In fact, the paper never could, it is designed only to tell you which candidates are worthy. From here your own eyes and your own taste must take over.

Wink

Congradulations Wink. No one could have said this better. The taste difference trade off is indeed between the larger flashes of sparkle and fire that come from larger mains and the smaller, more abundant sparkle/scintillation that comes from diamonds cut with larger pavilion halves and thinner mains.

To answer Echelon, there is no cliff in performance at 75% when it comes to lower half length. As I said earlier, GIA determined it to be a matter of taste down to 70% and AGS makes no explicit judgments about half length. They feel "If it gets the grade it gets the grade". The PGS software evaluates the integrated whole of the light performance.

I want to mention that my choice of 75% to 80% was not arbitrary. This is one of the 7 dimensions that I believe I showed in the article does have a peak, although a very broad one in the 75% to 80% vicinity, hence the choice of a 77% center.

I believe that if Wink, you and I compared your 74% LGF to the same diamond with 77% LGF both Wink and I would prefer your diamond and you would not likely see any difference at all.

My experience studying and analyzing various optically symmetric, super ideal cut diamonds, and talking to cutters of those diamonds, it that they tend to cut 76% to 78% LGF''s. So 77% is just the center and the labs both show from their respective grading systems, that it is a matter of taste, from at least 70% to 85%.

Ideal regards,

Michael

 

[Rhino]

Date: 7/19/2007 3:22:53 PM
Author: JohnQuixote

Date: 7/19/2007 2:37:54 PM
Author: Pyramid

Yes I remember seeing this but was just pointing out that the PGS software Serg used also agreed with Michael.

Not in a real sense Pyramid, because those are ''fantasy'' models, projected with perfect symmetry (impossible in real life). The lab doesn''t support it. We would need to have real-life examples to even speculate the chances for diamonds outside 0 on the cut guidelines to actually earn 0 (and then it would be speculation only). Michael''s projection is skewed because it included candidates all the way up to 42.2 PA. Meanwhile the cut guidelines figure 41.0 as a conservative ceiling for AGS0.

In reality I rarely see 41/34.5+ earn 0 in light performance. I have seen one example of 41/34.9 but never a 41/35 light performance DQD...much less anything remotely approaching the 42.2 used on that chart. Maybe Michael has real DQD samples? These would be useful to see. The point is, a diamond must actually go to the lab to earn the grade. My personal opinion is that the cut guidelines have more teeth for this application, since anything cut to their strictness is pretty much assured to earn 0. Outside that range it''s a stone-by-stone call.

In keeping with that, I want to reiterate that this is not about your diamond, which is beautiful and would earn top grades in any metric.

In reality John, there are hundreds of diamonds cut with this combo that receive AGS 0 all the time and by factories that do not cut for weight. Would you like to see many examples and that of stones with no notable light leakage via reflectors or any technology that detects leakage?

Have you ever taken real stones with 34.x crown angles and run them through PGS and see just where the 0-1 border is becuase the AGS charts are not an accurate indicator of the real cut offs. Curious.

 

[Rhino]

Date: 7/19/2007 3:28:57 PM
Author: JohnQuixote

Date: 7/19/2007 2:53:20 PM
Author: michaelgem



You are absolutely right John.

41 and 34 is just a point on a plateau, not necessarily any higher or lower than its surroundings, just happens to be in the center. What I thought remarkable was the discovery that GIA and AGS had almost identical centers...

Thanks Michael. I appreciate that and you know we see eye to eye on many things.

On the idea of ''center'' we interpret things differently. Fantasy brackets in sports are cool but there''s a reason they play the games. I think I am erring on the side of caution and you''re erring on the liberal side. Having statistics on actual samples would help, yes?

Not sure about linking via the forum but I have on hand here 34 AGS Ideal Cut diamonds and all with pavilion angles that would be rounded (by AGS) to 41.0 and they are all Ideal. Of those 34 diamonds 7 of them have crown angles greater than 34.5 degrees and these are diamonds being cut by a factory that doesn''t take chances by playing with borders. If you do an advanced search on our site you can search for crown and pavilion angles down to 1/100th of a degree and also by Lab, the grade the lab assisgned etc. Attached is an actual image I just snapped off of this stone we just received from this supplier so I don''t have the AGS Report in my hands yet but via our Sarin (which is in alignment with AGS'' Sarin) its a 34.75 crown with a 41.05 pavilion. God forbid, a 34.8/41.1 combo (thereabouts)!

When this diamond is placed alongside a 34.5/40.8 there is absolutely no visual difference whatsoever.

Octonus properly grades the stone 1.01 LR mono, .98 stereo and 1.01 for dark zone.

 

[Rhino]

The same stone under ASET. Point being, this is a critical look at how this proportion combo does via Octonus, Red Reflector and ASET. Digital technologies that perform light performance analysis correllate with the optical scopes as well.

Considering the realistic results of this AGS Graded 34.8/41.1 diamond, how much closer to the center is a 34/41 combo? Frankly I don''t know and I don''t care because I don''t purchase a diamond for inventory based off of numbers. I inspect its optics first and the numbers are an aftertyhought. Numbers are good for a general idea but to use them over or instead of common sense (especially in the face of hard evidence) and what they visually see is, and I''m sure you would agree, ludicrous. If you''d like to see more live examples let me know and I can post for ya however after today I do go on my lil vacation until the 30th.

 

[Rhino]

Date: 7/19/2007 8:28:46 PM
Author: elmo

Date: 7/19/2007 3:22:53 PM
Author: JohnQuixote
We would need to have real-life examples to even speculate the chances for diamonds outside 0 on the cut guidelines to actually earn 0 (and then it would be speculation only)...In reality I rarely see 41/34.5+ earn 0 in light performance. I have seen one example of 41/34.9 but never a 41/35 light performance DQD.

I linked a 41.0/35.1 here about five posts down.

Thanks for that elmo. I have seen absolutely beautiful 35/41 combos myself. Remember the crux or revelation of Henry Morse''s discovery in the late 1800''s was the awesome brightness he saw when cutting diamonds to the 35/41 combo. He came from a time where 45/45 was the norm.

 

[Rhino]

Date: 7/20/2007 7:21:28 AM
Author: Pyramid
I just wanted to add, I had thought stick with Whiteflash or Wink and that is the safest specs for a consumer to buy from, but why are they saying this, because all the diamonds they are selling have already got the AGS0 light return which mine has, I have been told mine is okay because it got this and not an AGS1 or 2 which diamonds could have got in the other specs. I know consumers not buying AGS0 certificates would see that as helpful but these vendors ARE selling AGS0. However, I have also thought there is an opposite side to this safety, the fact that although Jonathan is a vendor in the same way as they are, there are two unbiased opinions on the side of the steeper/deeper specs those of Michaelgem and Serg who are not selling diamonds.

I am afraid it makes no difference to a consumer who has spend a great deal of money on a diamond to be told her one got top grade but the type of parmeters it is cut too may not have got this grade. It leaves you feeling it is in a way more faulty in that it is near to the specs of those diamonds who may not get this grade. Now there is unbiased opinions here saying that Steeper Deeper diamonds would probably get AGS0 so who do we believe.

Yes to other consumers and I would be the first to think this too, this does not matter, do you like the look of the diamond etc but this does not help someone who is paying thousands of dollars and is hearing from experts different views, if it was two doctors debating something would you take a laypersons view? No. Yes it may be minutia or nano specs but consumers want to know what is better. At the moment I feel like returning my diamond and buying none.

Hi Pyramid,

I just want you to know that I completely understand where you are coming from. Although I believe John''s or Wink''s comments are not intended to induce fear into you, I can understand how they can and I totally support whatever decision you make. Because of my confidence in what I am saying and the reserach I conduct (and have conducted) I back my words and products, not just with the reputation we have earned or even the backing of Mike C, Serg, etc. but that of finance ie. I put my money where my mouth is. If for some reason experts agree in 1 day or 10 years from now that 34/41 is atrocious or not the best and can demonstrate why, or if you have remorse about your purchase for any reason, I will always take that diamond back on a trade for exactly what you paid. No time limits. No stipulations. You are never stuck. We have known each other here on the forums for a long time and the thought of offering inferior product or even secondary product is the farthest thing from my mind, especially considering the folks who come to this forum. It''s hard for me to imagine a long time person on these forums turn down such a rare gem with such rare optical characteristics that is, in no way 2nd to any other proportion combination. I just want you to know I support you 100% on whatever decision you make. I do think its a shame that you are being influenced in this manner though over something that is, what I consider a non-issue.

With kind regards,

 

[echelon6]

I''m relieved to see that there''s no cliff in performance at the boundaries of these sweetspot ranges. Personally I''m fine with an LGF of 74% as long as the issue is one of preference and not performance.

I do agree with the importance of seeing the stones in person but keep in mind that many PSers and clients coming from PS are shopping online for a reason. e.g. for me, no one in Sydney knows a thing about cut (I feel like we''re in the stone ages of cut research here - just take a look at the discussions on gemex.com.au and you''ll see). I''m deliberately buying sight unseen off US vendors because of the availability of all these numbers and scope images etc. They''re great, and my best chance of selecting a diamond that''s both mindclean and visually beautiful. So I do believe that full discuslore is not a wrong step here, and in fact, does help your sales.

To be honest, when I first came to PS, I brought along my original intended budget of around 4k (Jonathan can testify this when I first called him a month ago). Now, I''m playing around with 15k because my confidence in the product skyrocketed with all these numbers and scope images. The more consumer confidence you''re able to instill into your customers, the more value is added, and we''re willing to spend and pay more.



Pyramid, I''m sad to see that you''ve decided to return your stone, but you''re doing the right thing in the end. It''s definitely one of those "one-off'' purchases that you should get right the first time off. If you aren''t happy with it now, you won''t be happy with it in future, so best to solve the problem now, regardless of the merits of 41/34

 

[WinkHPD]

Date: 7/20/2007 10:29:18 AM
Author: michaelgem
I believe that if Wink, you and I compared your 74% LGF to the same diamond with 77% LGF both Wink and I would prefer your diamond and you would not likely see any difference at all.

Ideal regards,

Michael

LOL, I hear the old EightStar dealer in you coming to the forefront. I think you and I are finally in agreement, completely, about this comment.

I look forward to more agreements, and more disagreements. May they always be illuminating to those who read them.

Wink

 

[echelon6]

Date: 7/20/2007 9:38:55 AM
Author: Pyramid
I know you have to be in business to feed your wife, so does everyone in the whole world

HAH! That one made me lol... our sole purpose in life...

 

[pyramid]

Thanks Rhino.

 

[WinkHPD]

Oops, the sentence Contrary to popular Pricescope belief, the majority of the people buying diamonds today do not know nor care about anything but cut, color and price. Is a mistatement, it should read "clarity, color and price.

Too late to edit it, but it is a material difference to what I meant to say.

Wink

 

[pyramid]

Date: 7/20/2007 12:27:55 PM
Author: echelon6
Pyramid, I'm sad to see that you've decided to return your stone, but you're doing the right thing in the end. It's definitely one of those 'one-off' purchases that you should get right the first time off. If you aren't happy with it now, you won't be happy with it in future, so best to solve the problem now, regardless of the merits of 41/34

Thanks Ech

It is just a mind clean thing for me, in the same way this thread is about LGF% you were asking about that and that does not affect me at all, I would be quite happy there in the centre somewhere like 74, 75, 76, 77 because for me I like the width of those arrows, I feel the sparkle would be okay with either. However the pavillion is affecting me and it is probably for most people as I feel about the LGF% a nano subject but I am not happy with it. So although it is a mindclean thing I feel I have no option but to return the diamond. I have talked myself out of it a few times but I still come back to the same thing a few hours later.