True Hearts - Technical discussion

[Garry H (Cut Nut)]

Rhino I think it should be clear to you that the stone that started the other thread may not be called H&A''s by anyone who chooses to adehre to accepted standards.

But I have no doubt thet it is a beautiful diamond, just as many diamonds are that do not even have top symmetry.

You could go your own way and say that this is a GOG standard h&A''s.
You could do studies and surveys etc to prove that it is better than a sub 80% lg depth H&A''s as recognised by the rest of the world.

And everyone here who believes H&A''s have some special optical attributes should prove that too.

Till then I look on with mild amusement at this debate, and hope with fingers crossed that someone will indeed do something to prove their arguements are valid.

 

[Serg]

re:Every knowledgeable person on the subject (gemologist and layman) disagrees. Perfection & precision of cut can be identified by more than one optically symmetrical pattern and in no way is limited to 75-78% lower halves. To suggest otherwise is misleading information. I carry various types of precision cut diamonds that produce different optical patterns and I can show you diamonds with open hearts cut with much greater precision than some with closed hearts.

Rhino, Wink( or anybody)
Lets do REAL steps to check it.
I am waiting round diamond with bad symmetry ( 5.75-5.85 , VS-SI1, G-F) for what has same or better performance than H&A
We will do research and publish result and method of research. Anybody will have possibility repeat and check or results
You can also send Fancy diamonds for tests( but I do not promise what we will buy it for our MSS collection)

Do anybody want do input except discussions ?
Only 3 companies invest to MSS now( OctoNus, Lexus, Garry)
Again money is not most important issue , we need interesting samples.
A lot of persons are telling what they sell Best diamonds, where are these diamonds?

 

[John P]

Date: 8/1/2008 10:52:48 PM
Author: agc

Thanks John. Will the HRD system specify % cleft length needed to have low vs med vs high penalty such as 1-8% cleft= low penalty and 9-15% cleft = med penalty etc. ?

Regards
Andy

You're welcome Andy. Good question and no it doesn’t. The system is not measuring performance, it’s used to determine whether a round falls into the classification of traditional H&A or not. Like clarity grading - also unrelated to performance - they provide parameters and guidelines.

This is from the H&A cut parameters:

"Variation in the pavilion half length influences the gap between the v-shaped arrow head and the heart shape. Lowering the pavilion half length (79%) makes the gap between the V's and the hearts wider and creates incisions in the heart shapes. The arrows become thinner. It should be noticed that the range of acceptable half lengths is very narrow."

The "common parameter" for lower halves is cited as 77%.

When it comes to grading, the accept or reject decision (again, remember this is about patterning - not performance) is in the hands of the grader visually examining the shaping of the patterns in the viewer. There is some latitude there, per the below.

>

A graphic with “reject examples” is provided with the guidelines. Here are the first nine; H5 deals with incisions (acknowledgment to HRD).

 

[John P]

Date: 8/2/2008 12:52:55 AM
Author: Garry H (Cut Nut)

Rhino I think it should be clear to you that the stone that started the other thread may not be called H&A's by anyone who chooses to adehre to accepted standards.

But I have no doubt thet it is a beautiful diamond, just as many diamonds are that do not even have top symmetry.

You could go your own way and say that this is a GOG standard h&A's.

I hope we can all acknowledge the highlighted.

I know Rhino also carries true H&A rounds, in addition to diamonds like the one from the other thread and proprietary cuts & shapes other than round that are beautiful as well; many with top symmetry. Many do not fall into the "H&A” classification but that does not dilute their success or beauty. To that end I'm also a fan of Rhino developing another nomenclature as Garry suggests.

You could do studies and surveys etc to prove that it is better than a sub 80% lg depth H&A's as recognised by the rest of the world.

And everyone here who believes H&A's have some special optical attributes should prove that too.

Till then I look on with mild amusement at this debate, and hope with fingers crossed that someone will indeed do something to prove their arguements are valid.

There would be no argument if we could agree to separate the simple (traditional/historical) patterning topic from the performance topic. I know the Pricescope cut nerds - me included - have a hard time doing that.

 

[Paul-Antwerp]

Sergey,

May I ask you one question about the Master Stone Study?

Is it the intention to perform observations according to the pepsi-test-system, comparing one stone with another stone? Or will it be more in line with pharmaceutical testing with 20 stones having one characteristic being compared to 20 stones without that characteristic?

 

[adamasgem]

Date: 8/2/2008 12:34:22 PM
Author: Paul-Antwerp
Sergey,

May I ask you one question about the Master Stone Study?

Is it the intention to perform observations according to the pepsi-test-system, comparing one stone with another stone? Or will it be more in line with pharmaceutical testing with 20 stones having one characteristic being compared to 20 stones without that characteristic?

Paul I doubt Sergey, or anyone else doing research other than the 800# gorilla in the room, could afford to do pharmaceutical type testing.

My suggestion is some type of pertubation study, with random mathematical variances in STL files..

BUT, the FIRST thing, is agreement on the viewer concept, i.e. fixed angles regardless of stone size, the only thing that makes any sense.

 

[strmrdr]

Date: 8/2/2008 11:45:47 AM
Author: John Pollard

Date: 8/2/2008 12:52:55 AM

There would be no argument if we could agree to separate the simple (traditional/historical) patterning topic from the performance topic. I know the Pricescope cut nerds - me included - have a hard time doing that.

As you know I am a huge fan of patterning in diamonds as it relates to the real world and what people see.
Patterns takes you to the point of visibly symmetrical face up patterns but to me it does not justify viewing the diamonds upside down looking at patterns.
If it is anything other than marketing then to me its justification must be in performance.
When talking to people outside of PS.
1: very few know what H&A is.
2: The vast majority don''t care to know.
3: what they do want to know is does this diamond sparkle as well as it should and did I get a fair price.

Just yesterday when the subject came up with someone their comment was:
Yea the jeweler was babbling on about that trying to get me to spend more money. (HOF dealer)

 

[Rhino]

Greetings John & Wink,

Thanks for your response. My commentary below.

Date: 8/1/2008 7:43:20 PM
Author: John Pollard
Hi Rhino,

It might help to separate the two different topics that are tangled here; patterning and performance.

Since it has been clearly and properly brought out that that two are not one and the same I say we focus on the one element that is observed through a Hearts pattern. To use the words of the tutorial ... precision and perfection of cutting if indeed that is the aim.

Simple question ... which image (left or right) demonstrates a greater degree of precision and perfection in cutting? Or to put more simply which diamond has more precise Optical Symmetry?

Will comment further in my next post.

 

[John P]

Date: 8/2/2008 2:39:38 PM
Author: strmrdr

Date: 8/2/2008 11:45:47 AM
Author: John Pollard

Date: 8/2/2008 12:52:55 AM

There would be no argument if we could agree to separate the simple (traditional/historical) patterning topic from the performance topic. I know the Pricescope cut nerds - me included - have a hard time doing that.

As you know I am a huge fan of patterning in diamonds as it relates to the real world and what people see.

You and me both.

Patterns takes you to the point of visibly symmetrical face up patterns but to me it does not justify viewing the diamonds upside down looking at patterns.
If it is anything other than marketing then to me its justification must be in performance.
When talking to people outside of PS.
1: very few know what H&A is.
2: The vast majority don't care to know.

The vast majority don't even understand that grading labs are not regulated for equal color/clarity grades.

In the USA it's a small market that is made aware of this stuff. That won't change unless a major lab here starts grading optical symmetry (notice I did not say H&A). Alternately there are some cultures, especially in the Far East, that know a lot about traditional H&A and actively seek that patterning - as described in the PS tutorial - coupled with high clarity & color.

Many consumers I've talked to over the years (with emphasis on engineers and architects) are attracted to the concept; not only precision cutting, but of the birthplace and tradition of H&A too. I've had great success starting with education about the traditional H&A movement as a jumping-off point, and then discussing overall optical symmetry...not just in rounds...along with the benefits you allude to. I realize that diamonds with top optical symmetry are not for everyone, but they definitely have appeal to many.

3: what they do want to know is does this diamond sparkle as well as it should and did I get a fair price.

Definitely. And we should treat light performance as the most important component, regardless of whether it falls into the H&A classification or not.

I’ve been trying to find this example (thread): You posted it to identify different patterning within asschers; separate from performance.

"Different step patterns"

That is what HRD and the PS tutorial are doing when it comes to identifying the traditional H&A pattern within a round. It's one of many patterns possible - with historical precedence.

 

[Rhino]

...

TOPIC 1 - PATTERNING (aka shapes, aka geometry) - this is what the PS tutorial is about.

Question: Which shape, seen in the reflective H&A viewer, shows the pattern (geometric shape) that the PS tutorial and gemological bodies from the original Japanese labs to EGL, IGI, WGI and now HRD (all of the major labs grading H&A) consider ''Hearts?''

The answer is B.

All of the gemological bodies I listed above agree. There is no debate. It is a topic separate from optical performance.

Actually in reference to your first comment ... "this is what the PS tutorial is about".

It isn''t. It is stated clearly that the "aim of this tutorial is to demonstrate precision and perfection of cut"...

I submit to you that the Optical pattern formed by 75-78% lower halves (or if you want to extend to 80%) does not in any way demonstrate more ultimate precision and perfection in cutting than one with 82% lower halves.

My professional thoughts on this can be summed up in the following questions.

What exactly are we, as gemologists examining about these patterns?
Is it how pretty the diamond looks upside down? No because nobody mounts a diamond upside down.
Do one of these images demonstrate more precise cutting over the other? Again the answer is no as each of them are cut to equal levels of precision.
Does one demonstrate superior light performance in a practical observation? Again the answer is no although the nature of their optics will be different in a face up view (shorter vs longer lgfs).

So if a consumer purchases pattern A or C they are walking away from the PS Tutorial that options A or C have failed in precision and perfection of cutting.

This is my point.

Regarding what is called Hearts ...

Over the last decade consumers have come to equate the term "Hearts & Arrows" with precision cutting. For anyone to point to a particular (and I might add) perfectly symmetrical pattern and tell them it fails ... the obvious question is fails what?!?!?

Optical precision? No.
Light Performance? Again no.
Anything tangible to the subject of diamonds & gemology? No.

It fails one thing. Ones personal preference for a particular type of pattern. A preference I might add that should not be determined in a face down view under an H&A viewer but rather face up and with their own eyes in sufficient lighting to demonstrate the diamonds optics.

Debating the difference between the Hearts pattern formed by 82% lower halves vs 77% is akin to asking ... which graphic below constitues the true Heart?

To say the Hearts pattern in the upper left side is not a "true" Hearts pattern because it has larger clefts would be wrong. The fact is they are all Hearts patterns but with differing characteristics. Some have faint clefts, some are more pronounced ... the fact is they are all Hearts. One of these may conform to ones perception of what it should look like but it doesn''t disqualify the others.

At that point you are departing the subject of real gemology and getting into something akin to interior decorating and what pattern will look best on the wallpaper in a particular room except we are discussing something only observed in a viewer before the time of purchase.

I say the real subject at hand is what is actually observed from the Optical Symmetry image observed from the pavilion view. The real subject is precision and perfection of cutting and the pattern formed by 75-78% lower halves is one of many subsets that demonstrate the same phenomena. One does not pass and one does not fail because of the pattern formed as a result of lower half length. That is if your aim is to demonstrate precision and perfection of cutting as communicated through Optical Symmetry.

Peace,

 

[Rhino]

These demonstrate a tad more on my feelings on this ...

 

[Rhino]

and ...

 

[agc]

Date: 8/2/2008 3:46:52 PM
Author: Rhino
Greetings John & Wink,

Thanks for your response. My commentary below.

Date: 8/1/2008 7:43:20 PM
Author: John Pollard
Hi Rhino,

It might help to separate the two different topics that are tangled here; patterning and performance.

Since it has been clearly and properly brought out that that two are not one and the same I say we focus on the one element that is observed through a Hearts pattern. To use the words of the tutorial ... precision and perfection of cutting if indeed that is the aim.

Simple question ... which image (left or right) demonstrates a greater degree of precision and perfection in cutting? Or to put more simply which diamond has more precise Optical Symmetry?

Will comment further in my next post.

Jonathan, If I were looking for a diamond with the ultimate in precision/optical symmetry (when comparing the two diamond patterns your displaying in this post)I would lean toward the diamond with the cleft hearts over the true hearts one as both have symmetric hearts(I know the clefted ones are not true hearts) but the the true hearts one has variable V''s suggesting azimuth shift/yaw and the V''s are balanced in the clefted hearts. I feel overall the optical symmetry is therefore better in the clefted hearts example.(Of course everyone would also evaluate face up performance before choosing a diamond). This is where I have a problem with the H&A tutorial. The average consumer has little knowledge and the tutorial gives bias by starting off with "The aim of this tutorial is to illustrate what it takes to achieve the ultimate in cutting precision and perfection - super ideal cut Hearts and Arrows diamonds". IMHO this leads less knowledgable consumers to assume that the ultimate cut diamonds are super ideal H&A''s and everthing else is less. If the tutorial explained that this is a patterning issue and that some of the failures are due to not meeting historic patterning and not lack of cut/optical symmetry then it would be fine. It however lumps together diamonds with poor optical symmetry(missing hearts, different size hearts etc) with diamonds with perfectly symmetric clefted hearts that have just as high or higher precision/optical symmetry (as true H&A) but quickly gives them all the big "FAIL" without explanation. There is no comparison between a diamond with chaotic hearts and a diamond with perfect symmetrical clefted hearts with regard to optical symmetry yet the consumer is led to believe they are equal failures and not the ultimate like the true H&A. Since the aim of the tutorial and PS is education then clearing state/teach that this is historic patterning (not a guarantee of performance/beauty and that not all the failures are lacking in anyway the ultimate in cutting precision and perfection.(just in historic patterning).

 

[diagem]

Hi..., I am trying to catch up...., sorry and forgive my late simplistic question...

Date: 8/2/2008 12:52:55 AM
Author: Garry H (Cut Nut)
Rhino I think it should be clear to you that the stone that started the other thread may not be called H&A''s by anyone who chooses to adehre to accepted standards.

Garry who or what organizatrion set the H&A "accepted standards"?

But I have no doubt thet it is a beautiful diamond, just as many diamonds are that do not even have top symmetry.

You could go your own way and say that this is a GOG standard h&A''s.
You could do studies and surveys etc to prove that it is better than a sub 80% lg depth H&A''s as recognised by the rest of the world.

And everyone here who believes H&A''s have some special optical attributes should prove that too.

Till then I look on with mild amusement at this debate, and hope with fingers crossed that someone will indeed do something to prove their arguements are valid.

Me too

 

[John P]

Date: 8/2/2008 3:46:52 PM
Author: Rhino

Simple question ... which image (left or right) demonstrates a greater degree of precision and perfection in cutting? Or to put more simply which diamond has more precise Optical Symmetry?

Rhino, I appreciate what you are illustrating (nice graphics btw)

.

Answer: There is some slight weirdness in the image on the right, and I anticipate the point of your illustration is to demonstrate that some diamonds not classified as traditional “H&A” can be superior in cut precision to some that are classified as “H&A.” In fact, you can illustrate that showing a precisely cut princess...or a precisely cut asscher...or some 60/60 makes...next to true H&A candidates. I would not expect them to be classified as traditional H&A either.

You’ve repeatedly expressed discontent with two things in the PS tutorial:

1. The introductory statement

>

2. And the word > when it appears in the tutorial.

Why not lobby for those items to be reworded? Keep the tutorial’s information on how to create what the world knows as traditional “hearts and arrows” patterns intact. Instead of rewriting history, let’s just clear up any misunderstandings.

Otherwise, you’re trying to force Pricescope to disagree with the following:

The original, historic Japanese definitions
The parameters of the first labs to evaluate the H&A pattern
The H&A criteria of the world’s major labs who grade them
The H&A criteria of the world's current largest seller of branded H&A diamonds (HOF)
The H&A tutorial of the world’s current largest online seller of diamonds (BN)
The H&A tutorial of the world's current most trafficked diamond information site (PS)
(others not at the top of my mind)

A rewording that clears up potential confusion but keeps Pricescope’s accurate historical information intact seems a reasonable solution.

 

[adamasgem]

Seems to me a merchant out there wants to redefine what is supposedly called a "good" H&A cut for his/her own convenience, independent of the relative merits of the redefinition.

1) First, NO ONE has yet defined the parameters, for example, does a stone need to be seen in X's viewer or Y's viewer or is the definition based on a flawed measurement rendering?

2) Then, is the image scaled to a fixed angle viewer

3) I don't think one merchant has the right to redefine what has been accepted for so long, maybe that merchant has the better widget, then prove it by performance measures.H&A is a sales gimmic which also showed symmetry and precision cutting, IT DID NOT say anything about relative performance.

If some people like long LGFs then their stones probably won't be called top end H&A's, too bad for them, and if they try to call them that, they might wind up with a civil fraud case in their lap one orf these days, and then they will decide to stop what appears to be misrepresentation. Very nicely cut stones, but don't make the very ill, and possibly poorly defined criteria for H&A's.

 

[John P]

Date: 8/2/2008 5:42:52 PM
Author: agc

Jonathan, If I were looking for a diamond with the ultimate in precision/optical symmetry (when comparing the two diamond patterns your displaying in this post)I would lean toward the diamond with the cleft hearts over the true hearts one as both have symmetric hearts(I know the clefted ones are not true hearts) but the the true hearts one has variable V''s suggesting azimuth shift/yaw and the V''s are balanced in the clefted hearts. I feel overall the optical symmetry is therefore better in the clefted hearts example.(Of course everyone would also evaluate face up performance before choosing a diamond). This is where I have a problem with the H&A tutorial. The average consumer has little knowledge and the tutorial gives bias by starting off with ''The aim of this tutorial is to illustrate what it takes to achieve the ultimate in cutting precision and perfection - super ideal cut Hearts and Arrows diamonds''. IMHO this leads less knowledgable consumers to assume that the ultimate cut diamonds are super ideal H&A''s and everthing else is less. If the tutorial explained that this is a patterning issue and that some of the failures are due to not meeting historic patterning and not lack of cut/optical symmetry then it would be fine. It however lumps together diamonds with poor optical symmetry(missing hearts, different size hearts etc) with diamonds with perfectly symmetric clefted hearts that have just as high or higher precision/optical symmetry (as true H&A) but quickly gives them all the big ''FAIL'' without explanation. There is no comparison between a diamond with chaotic hearts and a diamond with perfect symmetrical clefted hearts with regard to optical symmetry yet the consumer is led to believe they are equal failures and not the ultimate like the true H&A. Since the aim of the tutorial and PS is education then clearing state/teach that this is historic patterning (not a guarantee of performance/beauty and that not all the failures are lacking in anyway the ultimate in cutting precision and perfection.(just in historic patterning).

Jinx!

(did anyone else play that game as a kid?)

 

[diagem]

Date: 8/2/2008 6:23:43 PM
Author: adamasgem
Seems to me a merchant out there wants to redefine what is supposedly called a ''good'' H&A cut for his/her own convenience, independent of the relative merits of the redefinition.

1) First, NO ONE has yet defined the parameters, for example, does a stone need to be seen in X''s viewer or Y''s viewer or is the definition based on a flawed measurement rendering?

2) Then, is the image scaled to a fixed angle viewer

3) I don''t think one merchant has the right to redefine what has been accepted for so long, maybe that merchant has the better widget, then prove it by performance measures.H&A is a sales gimmic which also showed symmetry and precision cutting, IT DID NOT say anything about relative performance.

If some people like long LGFs then their stones probably won''t be called top end H&A''s, too bad for them, and if they try to call them that, they might wind up with a civil fraud case in their lap one orf these days, and then they will decide to stop what appears to be misrepresentation. Very nicely cut stones, but don''t make the very ill, and possibly poorly defined criteria for H&A''s.

So to my humble understanding the H&A criteria is not well defined

? So why such a looong argument?

Sounds like everyone could be right on this one..., no??

 

[Serg]

Date: 8/2/2008 12:34:22 PM
Author: Paul-Antwerp
Sergey,

May I ask you one question about the Master Stone Study?

Is it the intention to perform observations according to the pepsi-test-system, comparing one stone with another stone? Or will it be more in line with pharmaceutical testing with 20 stones having one characteristic being compared to 20 stones without that characteristic?

Pual,

1) We are cutting 4 series 50 diamonds each for 2 mm diamonds.
2) For 0.7 ct we can not cut 20 diamonds for each characteristic
a) I do not like spend so much my money, you do not like spend money for MSS at all
b) I do not know company what can cut 20 clones asymmetrical diamonds

3) We compare diamonds in set 3-5 diamonds, Each set has same reference diamond
4) Tested person has not any information about samples
5) If you want invest enough money we will order 20 diamonds for each characteristic
6) 20 diamond for each characteristic is helpful , but we have idea how we can spend much more less money and receive helpful results
7) In most our tasks 20 diamonds for each characteristic is not very helpful because diamond has to much characteristics . Parametrical approach is dead even if same big Labs try use it even now
For some researchers observation even thousands diamonds is not enough.
But very important information you can receive from comparison just two diamonds

Quantity is important, but it is not enough for quality

And what is result my answers you? Are you happy do something now?

 

[diagem]

Date: 8/2/2008 5:20:44 AM
Author: Serg

re:Every knowledgeable person on the subject (gemologist and layman) disagrees. Perfection & precision of cut can be identified by more than one optically symmetrical pattern and in no way is limited to 75-78% lower halves. To suggest otherwise is misleading information. I carry various types of precision cut diamonds that produce different optical patterns and I can show you diamonds with open hearts cut with much greater precision than some with closed hearts.

Rhino, Wink( or anybody)
Lets do REAL steps to check it.

I am waiting round diamond with bad symmetry ( 5.75-5.85 , VS-SI1, G-F) for what has same or better performance than H&A
We will do research and publish result and method of research. Anybody will have possibility repeat and check or results

You can also send Fancy diamonds for tests( but I do not promise what we will buy it for our MSS collection)

Do anybody want do input except discussions ?
Only 3 companies invest to MSS now( OctoNus, Lexus, Garry)
Again money is not most important issue , we need interesting samples.
A lot of persons are telling what they sell Best diamonds, where are these diamonds?

Serg, are you running optimal/optical symmetry tests on all fancy shaped diamonds or just symmetrical even squares or shapes?
Is it even possible to run test on asymmetrical fancies? Can you decide on a common or average symmetrically contrast appearance on these shapes?

 

[John P]

AGC, your post also reminded me of a good point; the fact that all of these things are valued differently by different people.

I don't think optical symmetry is any more a "gimmick" (hi Marty

) than VVS+ clarity. Some people like the "idea" of clarity at the top of the scale. There are also people who like the "idea" of cut precision at the top of the scale. In fact, when coupled with great light return there are aspects of optical symmetry that are visible in performance, so I think the H&A movement - and optical symmetry in non-H&A rounds and other shapes - is less a gimmick than high clarity; which you pay for but will not possibly see.

With the above said, I have respect for whatever attributes make a person happy, personally.

 

[diagem]

Date: 8/2/2008 6:56:25 PM
Author: John Pollard
AGC, your post also reminded me of a good point; the fact that all of these things are valued differently by different people.

I don''t think optical symmetry is any more a ''gimmick'' (hi Marty

) than VVS+ clarity. Some people like the ''idea'' of clarity at the top of the scale. There are also people who like the ''idea'' of cut precision at the top of the scale. In fact, when coupled with great light return there are aspects of optical symmetry that are visible in performance, so I think the H&A movement - and optical symmetry in non-H&A rounds and other shapes - is less a gimmick than high clarity; which you pay for but will not possibly see.

With the above said, I have respect for whatever attributes make a person happy, personally.

Hi John...,

Hope all is well...

Do classify a "true" H&A in the same rarity level as natures VVS+ Diamond clarities?

 

[strmrdr]

Date: 8/2/2008 7:03:42 PM
Author: DiaGem

Do classify a ''true'' H&A in the same rarity level as natures VVS+ Diamond clarities?

not even close in my book as every piece of rough that will cut a round could be cut h&a no matter how many inclusions it has.

 

[strmrdr]

The question of why it was set at 80% still hasn''t been answered.
That''s a rather important question.

 

[strmrdr]

Date: 8/2/2008 6:23:43 PM
Author: adamasgem


If some people like long LGFs then their stones probably won''t be called top end H&A''s, too bad for them, and if they try to call them that, they might wind up with a civil fraud case in their lap one orf these days, and then they will decide to stop what appears to be misrepresentation. Very nicely cut stones, but don''t make the very ill, and possibly poorly defined criteria for H&A''s.

using that thinking anyone who sold an old system AGS0 as ideal can get sued too.
Bad standards get replaced all the time.

 

[John P]

Date: 8/2/2008 7:03:42 PM
Author: DiaGem

Date: 8/2/2008 6:56:25 PM
Author: John Pollard
AGC, your post also reminded me of a good point; the fact that all of these things are valued differently by different people.

I don''t think optical symmetry is any more a ''gimmick'' (hi Marty

) than VVS+ clarity. Some people like the ''idea'' of clarity at the top of the scale. There are also people who like the ''idea'' of cut precision at the top of the scale. In fact, when coupled with great light return there are aspects of optical symmetry that are visible in performance, so I think the H&A movement - and optical symmetry in non-H&A rounds and other shapes - is less a gimmick than high clarity; which you pay for but will not possibly see.

With the above said, I have respect for whatever attributes make a person happy, personally.

Hi John...,

Hope all is well...

Do classify a ''true'' H&A in the same rarity level as natures VVS+ Diamond clarities?

In today''s commercial production, absolutely. Walk through a mall in a US or European city with me. For every round we find that''s VVS2 or above you hand me a dollar. For every round showing H&A patterning I count as "true" I''ll give you a dollar.

 

[Serg]

Date: 8/2/2008 6:51:37 PM
Author: DiaGem

Date: 8/2/2008 5:20:44 AM
Author: Serg

re:Every knowledgeable person on the subject (gemologist and layman) disagrees. Perfection & precision of cut can be identified by more than one optically symmetrical pattern and in no way is limited to 75-78% lower halves. To suggest otherwise is misleading information. I carry various types of precision cut diamonds that produce different optical patterns and I can show you diamonds with open hearts cut with much greater precision than some with closed hearts.

Rhino, Wink( or anybody)
Lets do REAL steps to check it.


I am waiting round diamond with bad symmetry ( 5.75-5.85 , VS-SI1, G-F) for what has same or better performance than H&A
We will do research and publish result and method of research. Anybody will have possibility repeat and check or results


You can also send Fancy diamonds for tests( but I do not promise what we will buy it for our MSS collection)

Do anybody want do input except discussions ?
Only 3 companies invest to MSS now( OctoNus, Lexus, Garry)
Again money is not most important issue , we need interesting samples.
A lot of persons are telling what they sell Best diamonds, where are these diamonds?

Serg, are you running optimal/optical symmetry tests on all fancy shaped diamonds or just symmetrical even squares or shapes?
Is it even possible to run test on asymmetrical fancies? Can you decide on a common or average symmetrically contrast appearance on these shapes?

Diagem,

My task is to find ( or create) colorless fancy diamonds which has (obviously better for most consumers):
1) Total performance
2) Fire
3) Scintillation

It could be different fancy diamonds in each Category

I do not do any limitation in symmetry for such tests, but consumers usually prefer symmetrical diamonds

 

[strmrdr]

Date: 8/2/2008 3:53:18 PM
Author: John Pollard
Date: 8/2/2008 2:39:38 PM


I’ve been trying to find this example (thread): You posted it to identify different patterning within asschers; separate from performance.


'Different step patterns'

That is not correct and will take an article to cover.
But to keep it simple for now...
Face up contrast patterns is performance.
They are formed by virtual facets which are are the second key to diamonds performance with the angles being the first.
That is totally different than bottom up patterns.

 

[Serg]

Date: 8/2/2008 6:19:47 PM
Author: John Pollard

Date: 8/2/2008 3:46:52 PM
Author: Rhino

Simple question ... which image (left or right) demonstrates a greater degree of precision and perfection in cutting? Or to put more simply which diamond has more precise Optical Symmetry?

Rhino, I appreciate what you are illustrating (nice graphics btw)

.

Answer: There is some slight weirdness in the image on the right, and I anticipate the point of your illustration is to demonstrate that some diamonds not classified as traditional “H&A” can be superior in cut precision to some that are classified as “H&A.” In fact, you can illustrate that showing a precisely cut princess...or a precisely cut asscher...or some 60/60 makes...next to true H&A candidates. I would not expect them to be classified as traditional H&A either.

You’ve repeatedly expressed discontent with two things in the PS tutorial:

1. The introductory statement

<<The aim of this tutorial is to illustrate what it takes to achieve the ultimate in cutting precision and perfection - super ideal cut Hearts and Arrows diamonds>>

2. And the word <<fails>> when it appears in the tutorial.

Why not lobby for those items to be reworded? Keep the tutorial’s information on how to create what the world knows as traditional “hearts and arrows” patterns intact. Instead of rewriting history, let’s just clear up any misunderstandings.

Otherwise, you’re trying to force Pricescope to disagree with the following:

The original, historic Japanese definitions
The parameters of the first labs to evaluate the H&A pattern
The H&A criteria of the world’s major labs who grade them
The H&A criteria of the world's current largest seller of branded H&A diamonds (HOF)
The H&A tutorial of the world’s current largest online seller of diamonds (BN)
The H&A tutorial of the world's current most trafficked diamond information site (PS)
(others not at the top of my mind)

A rewording that clears up potential confusion but keeps Pricescope’s accurate historical information intact seems a reasonable solution.

How is about :

b] cut hearts and arrows diamonds>>

 

[adamasgem]

Date: 8/2/2008 7:40:23 PM
Author: strmrdr

Date: 8/2/2008 6:23:43 PM
Author: adamasgem


If some people like long LGFs then their stones probably won''t be called top end H&A''s, too bad for them, and if they try to call them that, they might wind up with a civil fraud case in their lap one orf these days, and then they will decide to stop what appears to be misrepresentation. Very nicely cut stones, but don''t make the very ill, and possibly poorly defined criteria for H&A''s.

using that thinking anyone who sold an old system AGS0 as ideal can get sued too.
Bad standards get replaced all the time.

Storm... Selling what may be termed "less than ideal" today based on yesterday''s criteria is slightly different than selling apples today when they are really oranges. One is a fraud, the other is not..