8-fold symmetry - just some theory

[strmrdr]

todays lessons in asscher virtual facets.
The virtual facets under the crown facets are small and generate small to med scint events.
The virtual facets under the table are huge and generate huge scint events.

Asschers don not work like rounds which have a much narrower range of virtual facet sizes.
If you study scint using rounds and princess cuts the asscher is going to destroy a lot of preconceived notions :}

 

[strmrdr]

Date: 2/13/2008 5:55:15 PM
Author: DiaGem

Date: 2/13/2008 5:48:31 PM
Author: strmrdr
DC war is on hehehehehe
In asschers draft + double refections more closely reflet the look of an asschers virtual facets:

Now do the same with a 40% table....

Do virtual facet perform more interestingly on step-cuts?

a 40% table 25% crown can not even began too be judged for scint using face up virtual facets.
They throw the rule book out even more compared too rounds and princess cuts.

 

[strmrdr]

32% table 30% crown height.. lots of virtual facets....

 

[strmrdr]

the crown virtual facets which are the smaller and midsized ones are as big or bigger than the largest of the RB virtual facets except in some cases the pavilion mains.
Which is the source of all the RB large scint events.
But the largest virtual facets still have more surface area than the largest RB's virtual facets including the mains.

 

[strmrdr]

as you tilt the asscher the virtual facets become bigger, which is why the largest flash from an asscher come at 15 to 22 degrees tilt.
Which btw is a very very common tilt on the hand :}

 

[strmrdr]

The proof is in the pudding...
15 degree tilt...
Also I saw it mentioned that AGS is only talking 15 degrees into account with scint... if so they are leaving one of the best shows any diamond can put on out of the picture...

 

[strmrdr]

now for the final proof...
Watch any of the asscher video's here, under spotlighting conditions and tilt and watch as the huge virtual facets fire :}
http://www.goodoldgold.com/video/

2+2 = 4
2+2+2 = 6
it all ties together in one neat little bundle :}

btw storm rules as my good friend would say hehehehehehehehehehe

 

[WinkHPD]

Date: 2/13/2008 5:35:06 PM
Author: DiaGem

Date: 2/13/2008 5:05:34 PM
Author: Wink
In my response above I expressed my opinion of what virtual facets were, roughly, and Todd expressed a similar but diametrically opposed opinion. Todd, Paul Slegers, John Pollard and I have since had discussions about this, and it helps me to better understand what some of the light scientists are talking about in a more thorough manner than my previous post and adds a further dimension into the discussion because it also takes into consideration not only optical symmetry, but also tilt and its affect on the appearance and performance of virtual facets.

I am going to enclose a portion of that discussion, with Paul and John''s permission, in this post for you to understand a little better not only the complexity of the issue, but the depth of their understanding of it. I have had the great fortune of sitting in a room with John Pollard and Peter Yantzer of the AGS and listening to them discuss this same issue, and trust me, it is incredibly complex. Some of the greatest minds on the planet have attacked this issue of diamond performance and its affect on scintillation and they are not yet fully satisfied that they have captured the full essence of it, but they are definitely getting close!

Here is the result of an email discussion between some of us who are cut obsessed. Thanks to John P for the graphics. I think my mind is finally beginning to actually absorb this as it seems quite straight forward this time. For those who wish further explanation, perhaps someone who is more search literate can find the threads where we discussed the issues of the length of the flash of color and the need for it to be longer than the width of the pupil for the dispersion to actually show. I particularly enjoyed the reference to Marty Haske''s work.

Virtual facets are the appearance of smaller facets within larger facets, in the form of surfaces or images, which occur due to reflection and refraction within a diamond. You can see simulated virtual facets in DiamCalc by selecting ''Draft + Single Reflection'' (see virtualfacet-01.jpg and virtualfacet-02.jpg). Remember that when looking at the computer-example in this graphic there is an assumption of perfect optical symmetry [cut precision] and no tilt. Since Infinity diamonds are cut with such high precision it is applicable to our product for this example, but the vast majority of diamonds in ''real life'' would display very chaotic, unordered virtual facets even in a perfectly non-tilted position.

I would imagine ''chaotic'' virtual facets could make the appearance of a Diamond more interesting while being less uniformed.

Looking at virtualfacet-03.jpg you can see that as our diamond tilts the frequency and size of the virtual facets shifts and changes. As we go to 5, 10 and 15 degrees ''south'' and ''east'' the frequency of the virtual facets increases and their size decreases. In such a small object it''s easy to see how fast these virtual facets become tiny and reduce the possibility of seeing fire (understanding AGS research on fire mapping/human vision aids comprehension of this). Since the AGS light performance system accounts for how a diamond fares when tilted to 15 degrees at different compass points - another example of how they are leading the field – we can easily understand how round and princess diamonds with top optical symmetry [cut precision] and proper facet structure for their size [chevrons on princess] are scoring well in terms of scintillation: More ''scintillation events'' in the medium and large range are visile with such stones through a practical range of tilt.

I would imagine that RB''s with shorter lgf''s or Princess cuts with fewer and wider chevron facets would have even larger ''scint. events'' ..., but then i understand they might be dropped off the Ideal cut list...
Could be a type of catch 22....

There is even more to come regarding not only the size of the events but the intensity of color: Marty Haske, a leading specialist in diamond optics, has done research showing that top optical symmetry [cut precision] results in purer spectral hues during scintillation. This is because virtual facets in precisely cut stones are more orderly so the fresnels don''t mix. Put in simple terms, precisely cut stones have less color-mixing in their scintillation so your eye will see more intense, pure-colored flares than the mixed pastels and earth tones seen in less precisely cut diamonds.

Again..., I would imagine more color mixing in the scint. might be somehow more desirable...., maybe???

There you have it, direct from the mouth, or should I say fingers, of Paul Slegers, with additional reference to the research of Marty Haske.

Wink

It sounds to me that the whole issue of scintillation could easily fall into the beauty category of:

''Beauty is in the eye of the beholder''....

Me for example...., I am not too fond on uniformed appearances..., just my personal opinion....

And the conversation continues:

DiaGem replies…


In general, sure. We all know precise optical symmetry is not a requirement for diamond beauty in terms of taste. But when it comes to scintillation events (which is specifically what I was talking about) virtual facets only benefit appearance if they are large enough to be detected. The problem with asymmetry is that the virtual facets are broken faster into smaller sizes, reducing both the chance to see the flashes and to see fire in them, since the human pupil ‘clips’ it at different points (this goes back to the AGS fire map studies). Maybe you’ve seen these proprietary cut with very high facet counts in 1ct sizes DG? If so, you know how “jumbled” they can look and why the scint qualities seem less colorful. These scintillation studies are explaining why in a scientific sense. So, to capsulize this comment. You might see more sparkle, but less color. Me I like color. If you like more sparkle, that is okay too.

Could be a type of catch 22....

I completely agree with the first part of the statement. What we must remember is that frequency is also a component of scintillation. AGS and GIA both have 77.5% as the center of their optimum range for LGF in conventional round makes. You can go lower, but too far and you trade off too much frequency for the size of events. There is a great presentation from AGS at the last JCK which modeled scint events in a cushion cut, tolkowsky cut and leo cut and you can see that all three score well in their individual harmony of frequency to size. Different looks but equally high scores. In the same study they showed Princess cut diamonds with 2,3 and 4 chevrons and you are right – the smaller the diamond the more appropriate it is to have less chevrons for the very thing you describe. Fortunately, the AGS metric does not discriminate as long as there is harmony in size and frequency. They are doing a good job of explaining why people can feel, for example, a cushion and a round have equally effective performance even though they look different. If you have not seen it, email John P as I think he might have that presentation linked at a url on his domain. (Anybody''s head hurting yet? if not, go back and reread the above, it hurt!)

b]

Maybe, but only insofar as the eye can see the events. Also, when it comes to pastels and earth tones, that is somewhat of a taste thing but it will also be about the intensity of the events: When the fresnels mix that intensity is reduced, so someone who likes somewhat muted but beautiful earth tones and someone else who prefers big bright blues, reds and greens may like two different diamonds. Even as I say this I would also say that the virtual facet research is pretty solid, while this business about the fresnels mixing has not been officially presented (yet), although it agrees with what I have seen over time. Maybe Marty Haske will visit and clarify. (The Fresnell reflections are where you are getting mixed light from two different places, which is why the "points" of the "arrows" look lighter in color than the "shafts".)

So, personal taste does enter into the equation as to what you like, but NOT as to the science of what is happening in the gem in question.

Just more thoughts after exhaustive conversations with some of the masters, including but not limited to Paul, John, Todd, Peter, (but not today with Peter) et all. I really hope Marte will chime in, I did not get to talk with him today, but he REALLY knows what I am explaining and can go into MUCH greater depth.

Wink

 

[strmrdr]

Date: 2/13/2008 7:29:08 PM
Author: Wink

<< Again..., I would imagine more color mixing in the scint. might be somehow more desirable...., maybe???

Maybe, but only insofar as the eye can see the events. Also, when it comes to pastels and earth tones, that is somewhat of a taste thing but it will also be about the intensity of the events: When the fresnels mix that intensity is reduced, so someone who likes somewhat muted but beautiful earth tones and someone else who prefers big bright blues, reds and greens may like two different diamonds. Even as I say this I would also say that the virtual facet research is pretty solid, while this business about the fresnels mixing has not been officially presented (yet), although it agrees with what I have seen over time. Maybe Marty Haske will visit and clarify. (The Fresnell reflections are where you are getting mixed light from two different places, which is why the ''points'' of the ''arrows'' look lighter in color than the ''shafts''.)

So, personal taste does enter into the equation as to what you like, but NOT as to the science of what is happening in the gem in question.

Just more thoughts after exhaustive conversations with some of the masters, including but not limited to Paul, John, Todd, Peter, (but not today with Peter) et all. I really hope Marte will chime in, I did not get to talk with him today, but he REALLY knows what I am explaining and can go into MUCH greater depth.

Wink

hmm well I think that the pure tone theory is interesting and it may well be that optical symmetrical stones separate color into more pure tones but....
Who walks around with a cri 98 lamp over their diamond all the time?
http://www.lumiram.com/fluorescent.html
In any lighting condition even outside under sunlight in the middle of nowhere there are going to be peaks and valleys in the lighting spectrum hitting the diamond so all the sudden those pure tones aren''t very pure anymore......
Worse would be lighting inside where every source of lighting even pure white bulbs have a distint spectrum.

 

[WinkHPD]

I think we are talking about different things. Independant of the light source the more symmetry, the more medium to large scintillation events that can separate the light into the colors that it contains. It is the colors in the light that are being separated, no one is saying the gem can create colors that are not in the light that is hitting the gem.

It is one of the latest frontiers in the study of light and how it acts in a gem, and far better minds than mine are working hard on it. I am just reporting my understanding of that science and the studies that are being done.

There is still plenty of room for personal taste. I have seen scintillation and great separation of light in my diamonds in just about every light that you can imagine. Don''t get much (any) scintillation in a dark environment with a blue light, but in low light, outside light, inside fluorescent, and especially in incandescent light I see varying degrees and quantities.

Wink

 

[Garry H (Cut Nut)]

Date: 2/13/2008 10:31:57 PM
Author: Wink
I think we are talking about different things. Independant of the light source the more symmetry, the more medium to large scintillation events that can separate the light into the colors that it contains. It is the colors in the light that are being separated, no one is saying the gem can create colors that are not in the light that is hitting the gem.

It is one of the latest frontiers in the study of light and how it acts in a gem, and far better minds than mine are working hard on it. I am just reporting my understanding of that science and the studies that are being done.

There is still plenty of room for personal taste. I have seen scintillation and great separation of light in my diamonds in just about every light that you can imagine. Don''t get much (any) scintillation in a dark environment with a blue light, but in low light, outside light, inside fluorescent, and especially in incandescent light I see varying degrees and quantities.

Wink

Wink it is impossible to see any other colour than a spectral color. There is no mixing of wavelengths unless the gemstone is doubly refractive like this faceted calcite from the Smithsonian. (Diamond is singly refractive)

The only issue is if you have a light source that is devoid of certain colours - then you will not get much of that fire.
There are no muted mixed colours in diamond no matter what happens with symmetry.
and there is very little mid frequency (green) fire - if you want to know why I can find some links on the Russian site. But it was discussed here http://journal.pricescope.com/Articles/50/5/Letter-to-the-Editor-of-the-Australian-Gemmologist.aspx

 

[Garry H (Cut Nut)]

oops

 

[strmrdr]

Date: 2/13/2008 10:31:57 PM
Author: Wink
I think we are talking about different things. Independant of the light source the more symmetry, the more medium to large scintillation events that can separate the light into the colors that it contains. It is the colors in the light that are being separated, no one is saying the gem can create colors that are not in the light that is hitting the gem.

It is one of the latest frontiers in the study of light and how it acts in a gem, and far better minds than mine are working hard on it. I am just reporting my understanding of that science and the studies that are being done.

There is still plenty of room for personal taste. I have seen scintillation and great separation of light in my diamonds in just about every light that you can imagine. Don''t get much (any) scintillation in a dark environment with a blue light, but in low light, outside light, inside fluorescent, and especially in incandescent light I see varying degrees and quantities.

Wink

We are talking about the same thing.....
Its been discussed about a hundred times on here I find it interesting but I don''t buy into it yet.
Nor do I really care about it because I think its misdirection from where the research really needs too go.

The most pure colors I have ever seen come off a diamond were from a rather poorly cut oec that was dead in diffused lighting but a disco ball in spot lighting.
Large chunks of fire all over the place.
Nice but the hof it was next too was a better all around diamond.

 

[strmrdr]

I would like too apologize if any of my posts come across sounding rude in this thread.
The virtual facets is something I have spent hours and hours and hours on with asschers.
They are an integral part of my design process when I am working on my designs.

Storm

 

[adamasgem]

Date: 2/13/2008 8:26:35 PM
Author: strmrdr

Date: 2/13/2008 7:29:08 PM
Author: Wink

<< Again..., I would imagine more color mixing in the scint. might be somehow more desirable...., maybe???

Maybe, but only insofar as the eye can see the events. Also, when it comes to pastels and earth tones, that is somewhat of a taste thing but it will also be about the intensity of the events: When the fresnels mix that intensity is reduced, so someone who likes somewhat muted but beautiful earth tones and someone else who prefers big bright blues, reds and greens may like two different diamonds. Even as I say this I would also say that the virtual facet research is pretty solid, while this business about the fresnels mixing has not been officially presented (yet), although it agrees with what I have seen over time. Maybe Marty Haske will visit and clarify. (The Fresnell reflections are where you are getting mixed light from two different places, which is why the ''points'' of the ''arrows'' look lighter in color than the ''shafts''.)

So, personal taste does enter into the equation as to what you like, but NOT as to the science of what is happening in the gem in question.

Just more thoughts after exhaustive conversations with some of the masters, including but not limited to Paul, John, Todd, Peter, (but not today with Peter) et all. I really hope Marte will chime in, I did not get to talk with him today, but he REALLY knows what I am explaining and can go into MUCH greater depth.

Wink

hmm well I think that the pure tone theory is interesting and it may well be that optical symmetrical stones separate color into more pure tones but....
Who walks around with a cri 98 lamp over their diamond all the time?
http://www.lumiram.com/fluorescent.html
In any lighting condition even outside under sunlight in the middle of nowhere there are going to be peaks and valleys in the lighting spectrum hitting the diamond so all the sudden those pure tones aren''t very pure anymore......
Worse would be lighting inside where every source of lighting even pure white bulbs have a distint spectrum.

In the work I did to develop US Patent 7315356, the data showed that optical symmetry = broad flash fire (larger virtual facets) and purer spectral hues in the RBC. I did not look at other cuts. One could actually show the correlation in both the photographed pattern and fire and the original AGS grades as done in 2003.

I have not studied the complex mathematics that cause what I see..

Marty

P.S. I usually don''t monitor PS threads as I am very busy with SAS2000 builds and software development, so send me an email if you want specific comments with a link to the thread.

 

[adamasgem]

Date: 2/13/2008 11:05:18 PM
Author: Garry H (Cut Nut)

Wink it is impossible to see any other colour than a spectral color. There is no mixing of wavelengths unless the gemstone is doubly refractive like this faceted calcite from the Smithsonian. (Diamond is singly refractive)

Garry.. You might rethink your comment. Is white a spectral color?

 

[strmrdr]

Date: 2/14/2008 12:19:42 AM
Author: adamasgem
In the work I did to develop US Patent 7315356, the data showed that optical symmetry = broad flash fire (larger virtual facets) and purer spectral hues in the RBC. I did not look at other cuts. One could actually show the correlation in both the photographed pattern and fire and the original AGS grades as done in 2003.

I have not studied the complex mathematics that cause what I see..

Marty

P.S. I usually don''t monitor PS threads as I am very busy with SAS2000 builds and software development, so send me an email if you want specific comments with a link to the thread.

rofl the first time you mentioned such a device I broke out a pencil and drew a sketch that is about 90% similar too that.

If you say you see it in your device I believe ya, but the usefulness and if it means anything real world is what I question....

 

[Garry H (Cut Nut)]

Date: 2/14/2008 12:28:31 AM
Author: adamasgem

Date: 2/13/2008 11:05:18 PM
Author: Garry H (Cut Nut)

Wink it is impossible to see any other colour than a spectral color. There is no mixing of wavelengths unless the gemstone is doubly refractive like this faceted calcite from the Smithsonian. (Diamond is singly refractive)

Garry.. You might rethink your comment. Is white a spectral color?

Hi mate, no need to rethink Marty
http://www.gemology.ru/cut/english/grading1/4.htm

 

[diagem]

style="WIDTH: 95.18%; HEIGHT: 1285px">

And the conversation continues:

DiaGem replies…

<< I would imagine ''chaotic'' virtual facets could make the appearance of a Diamond more interesting while being less uniformed.

In general, sure. We all know precise optical symmetry is not a requirement for diamond beauty in terms of taste. But when it comes to scintillation events (which is specifically what I was talking about) virtual facets only benefit appearance if they are large enough to be detected. The problem with asymmetry is that the virtual facets are broken faster into smaller sizes, reducing both the chance to see the flashes and to see fire in them, since the human pupil ‘clips’ it at different points (this goes back to the AGS fire map studies). Maybe you’ve seen these proprietary cut with very high facet counts in 1ct sizes DG? If so, you know how “jumbled” they can look and why the scint qualities seem less colorful. These scintillation studies are explaining why in a scientific sense. So, to capsulize this comment. You might see more sparkle, but less color. Me I like color. If you like more sparkle, that is okay too.

Wink..., is that a statement? I would tend to disagree with that..., there is a possibility you are partially correct off-course..., but I would think the opposite is more likely..., in any way..., neither you or I can say for sure if the virtual facets in a specific asymmetrical Diamond will break into smaller or bigger sizes..., until scientifically tested!

It doesn''t make sense you saying "You might see more sparkle, but less color."..., I would say it too is dependant on what specific example you are talking about....

<< I would imagine that RB''s with shorter lgf''s or Princess cuts with fewer and wider chevron facets would have even larger ''scint. events'' ...., but then i understand they might be dropped off the Ideal cut list...
Could be a type of catch 22....

I completely agree with the first part of the statement. What we must remember is that frequency is also a component of scintillation. AGS and GIA both have 77.5% as the center of their optimum range for LGF in conventional round makes.

What is the shortest lgf that still fall in the EX or ideal range?

You can go lower, but too far and you trade off too much frequency for the size of events. There is a great presentation from AGS at the last JCK which modeled scint events in a cushion cut, tolkowsky cut and leo cut and you can see that all three score well in their individual harmony of frequency to size. Different looks but equally high scores. In the same study they showed Princess cut diamonds with 2,3 and 4 chevrons and you are right – the smaller the diamond the more appropriate it is to have less chevrons for the very thing you describe. Fortunately, the AGS metric does not discriminate as long as there is harmony in size and frequency. They are doing a good job of explaining why people can feel, for example, a cushion and a round have equally effective performance even though they look different. If you have not seen it, email John P as I think he might have that presentation linked at a url on his domain. (Anybody''s head hurting yet? if not, go back and reread the above, it hurt!)

<< Again..., I would imagine more color mixing in the scint. might be somehow more desirable...., maybe???

Maybe, but only insofar as the eye can see the events. Also, when it comes to pastels and earth tones, that is somewhat of a taste thing but it will also be about the intensity of the events: When the fresnels mix that intensity is reduced, so someone who likes somewhat muted but beautiful PASTEL AND earth tones and someone else who prefers big bright blues, reds and greens may like two different diamonds. Even as I say this I would also say that the virtual facet research is pretty solid, while this business about the fresnels mixing has not been officially presented (yet), although it agrees with what I have seen over time. Maybe Marty Haske will visit and clarify. (The Fresnell reflections are where you are getting mixed light from two different places, which is why the ''points'' of the ''arrows'' look lighter in color than the ''shafts''.)

I would think fresnells appear mainly of the edges of (virtual) facets..., and will be more noticeable on narrow geometric shapes vs. the larger straight edge shapes...

So, personal taste does enter into the equation as to what you like, but NOT as to the science of what is happening in the gem in question.

Just more thoughts after exhaustive conversations with some of the masters, including but not limited to Paul, John, Todd, Peter, (but not today with Peter) et all. I really hope Marte will chime in, I did not get to talk with him today, but he REALLY knows what I am explaining and can go into MUCH greater depth.

I think I asked you that before (and never got an answer...), please define master in your written example?

Wink

 

[diagem]

Date: 2/13/2008 10:31:57 PM
Author: Wink
I think we are talking about different things. Independant of the light source the more symmetry, the more medium to large scintillation events that can separate the light into the colors that it contains. It is the colors in the light that are being separated, no one is saying the gem can create colors that are not in the light that is hitting the gem.

It is one of the latest frontiers in the study of light and how it acts in a gem, and far better minds than mine are working hard on it. I am just reporting my understanding of that science and the studies that are being done.

There is still plenty of room for personal taste. I have seen scintillation and great separation of light in my diamonds in just about every light that you can imagine. Don''t get much (any) scintillation in a dark environment with a blue light, but in low light, outside light, inside fluorescent, and especially in incandescent light I see varying degrees and quantities.

Wink

???

Wink...., do you mean "uniformed"?

 

[Garry H (Cut Nut)]

Date: 2/14/2008 6:28:21 AM
Author: DiaGem

Date: 2/13/2008 10:31:57 PM
Author: Wink
I think we are talking about different things. Independant of the light source the more symmetry, the more medium to large scintillation events that can separate the light into the colors that it contains. It is the colors in the light that are being separated, no one is saying the gem can create colors that are not in the light that is hitting the gem.

It is one of the latest frontiers in the study of light and how it acts in a gem, and far better minds than mine are working hard on it. I am just reporting my understanding of that science and the studies that are being done.

There is still plenty of room for personal taste. I have seen scintillation and great separation of light in my diamonds in just about every light that you can imagine. Don''t get much (any) scintillation in a dark environment with a blue light, but in low light, outside light, inside fluorescent, and especially in incandescent light I see varying degrees and quantities.

Wink

???

Wink...., do you mean ''uniformed''?

Lets cut with less facets to get bigger flashes, short LG''s or old cuts and rose cuts?

BTW a virtual facet is a window to a point or direction in space. Most are so small that to be able to see 2 diffferent light sources and therefore get a mixing of colours can only occur in a device like Marty''s where there are millions of tiny close together light sources. The smaller the virtual facet, the less chance you can see the fabled fresnel mixing.

 

[diagem]

Date: 2/14/2008 7:57:17 AM
Author: Garry H (Cut Nut)

Date: 2/14/2008 6:28:21 AM
Author: DiaGem

Date: 2/13/2008 10:31:57 PM
Author: Wink
I think we are talking about different things. Independant of the light source the more symmetry, the more medium to large scintillation events that can separate the light into the colors that it contains. It is the colors in the light that are being separated, no one is saying the gem can create colors that are not in the light that is hitting the gem.

It is one of the latest frontiers in the study of light and how it acts in a gem, and far better minds than mine are working hard on it. I am just reporting my understanding of that science and the studies that are being done.

There is still plenty of room for personal taste. I have seen scintillation and great separation of light in my diamonds in just about every light that you can imagine. Don''t get much (any) scintillation in a dark environment with a blue light, but in low light, outside light, inside fluorescent, and especially in incandescent light I see varying degrees and quantities.

Wink

???

Wink...., do you mean ''uniformed''?

Lets cut with less facets to get bigger flashes, short LG''s or old cuts and rose cuts?

BTW a virtual facet is a window to a point or direction in space. Most are so small that to be able to see 2 diffferent light sources and therefore get a mixing of colours can only occur in a device like Marty''s where there are millions of tiny close together light sources. The smaller the virtual facet, the less chance you can see the fabled fresnel mixing.

Like I said above..., CATCH 22...

I wish a Diamond could look like the pictures Marty (or someone on his behalf) posted a while back..., but in reality...., the flashes should be a noticeable size..., not too large nor too small.

But I must admit..., I have seen some OEC''s that will out-win any modern RB in face-up beauty and character..., (but thats my humble opinion!

)

 

[adamasgem]

Date: 2/14/2008 12:52:22 AM
Author: Garry H (Cut Nut)

Date: 2/14/2008 12:28:31 AM
Author: adamasgem

Date: 2/13/2008 11:05:18 PM
Author: Garry H (Cut Nut)

Wink it is impossible to see any other colour than a spectral color. There is no mixing of wavelengths unless the gemstone is doubly refractive like this faceted calcite from the Smithsonian. (Diamond is singly refractive)

Garry.. You might rethink your comment. Is white a spectral color?

Hi mate, no need to rethink Marty
http://www.gemology.ru/cut/english/grading1/4.htm

Garry.. Cut effects the ability to resolve spectral colors

 

[WinkHPD]

Date: 2/14/2008 5:33:36 AM
Author: DiaGem

I think I asked you that before (and never got an answer...), please define master in your written example?

You may have, I do not remember being asked, but a good and fair question.

Perhaps I use the term differently than you would and I certainly do not use it as it would be used in a guild where there were masters and apprentices, although in many ways that would be correct.

In my mind, and what I speak is as it is in my mind, a master is someone that I respect and admire and in some cases am fortunate enough to call friend. The masters are also people that I believe to have a deep and profound understanding of the topic at hand and who are willing to let the facts lead them to their conclusions, not their desire to prove one point or another. Some of them are also my heroes in the very real sense that I admire them and strive to be worthy of their friendship and camaraderie.

I have many such people in mind and in many industries and walks of life. In this business I can name many obvious people who qualify in my mind. Peter Yantzer of course is one of them, as are Jim Caudill and Q, both co workers of his who have brought incredible knowledge to the industry, whether or not the industry wanted it. I believe Peter''s brother at the GIA is another, although I do not know him well, what I do know I highly respect. Paul Slegers is high on the list, as is John Pollard who has become a great friend and who has spent hours helping me to understand the complexities of light science as he understands it from his hours with others. Brian the Cutter joins Paul as one of the people who strive to bring a consistent level of beauty to the public, and who has spent his life also in the pursuit of understanding the gems that he works with. Marte Haske certainly belongs on the list as does Richard von Sternberg. All of those people have a profound knowledge of the subject and have spent time assisting me to understand it.

Sergei from Moscow I do not know personally but I certainly admire his work and of course Gary Holloway from upside down land, although I often disagree with him about things, some more minor than others. (Just because he is a master in my book does not mean he is always right in my book.)

Throw in colored gems and you must start another list, headed by the incredible Richard Homer and I could go on and on.

If you are looking for a definition that you can hang a qualification on, sorry, I can not give it to you. So did I use the term incorrectly? For you, probably, for me, no.

I will try to be aware that I am not necessarily speaking to people who will understand that I do not use that title as a title of professional recognition, that it is a title I use as a compliment to their outstandingness in my life. As such I probably should not use it without qualification, and if I caused you confusion or irritation I apologize.

But since you asked, that is what I mean by a master.

Wink

 

[diagem]

Date: 2/14/2008 11:00:40 AM
Author: Wink

Date: 2/14/2008 5:33:36 AM
Author: DiaGem

I think I asked you that before (and never got an answer...), please define master in your written example?

You may have, I do not remember being asked, but a good and fair question.

Perhaps I use the term differently than you would and I certainly do not use it as it would be used in a guild where there were masters and apprentices, although in many ways that would be correct.

In my mind, and what I speak is as it is in my mind, a master is someone that I respect and admire and in some cases am fortunate enough to call friend. The masters are also people that I believe to have a deep and profound understanding of the topic at hand and who are willing to let the facts lead them to their conclusions, not their desire to prove one point or another. Some of them are also my heroes in the very real sense that I admire them and strive to be worthy of their friendship and camaraderie.

I have many such people in mind and in many industries and walks of life. In this business I can name many obvious people who qualify in my mind. Peter Yantzer of course is one of them, as are Jim Caudill and Q, both co workers of his who have brought incredible knowledge to the industry, whether or not the industry wanted it. I believe Peter''s brother at the GIA is another, although I do not know him well, what I do know I highly respect. Paul Slegers is high on the list, as is John Pollard who has become a great friend and who has spent hours helping me to understand the complexities of light science as he understands it from his hours with others. Brian the Cutter joins Paul as one of the people who strive to bring a consistent level of beauty to the public, and who has spent his life also in the pursuit of understanding the gems that he works with. Marte Haske certainly belongs on the list as does Richard von Sternberg. All of those people have a profound knowledge of the subject and have spent time assisting me to understand it.

Sergei from Moscow I do not know personally but I certainly admire his work and of course Gary Holloway from upside down land, although I often disagree with him about things, some more minor than others. (Just because he is a master in my book does not mean he is always right in my book.)

Throw in colored gems and you must start another list, headed by the incredible Richard Homer and I could go on and on.

If you are looking for a definition that you can hang a qualification on, sorry, I can not give it to you. So did I use the term incorrectly? For you, probably, for me, no.

I will try to be aware that I am not necessarily speaking to people who will understand that I do not use that title as a title of professional recognition, that it is a title I use as a compliment to their outstandingness in my life. As such I probably should not use it without qualification, and if I caused you confusion or irritation I apologize.

But since you asked, that is what I mean by a master.

Wink

Wink, thank you for explaining your personal meaning of the term "Master" (or as used previously..., "Master Cutter")
As per your explanation...,I dont think you use the term incorrectly..., just wanted to know as you seem to use this term numerous times on a wide public forum.

This rare "title of professional recognition" does exist among some selected few.....

 

[strmrdr]

Wink,
Sounds like a case of hero worship lol (had to razz ya a little)

Now some people on your list iv got a lot of respect for when it comes too rounds and too a lesser extent princess cuts but there is a very distinct gap when it comes too asschers.
The AGS asscher grading is a total failure not even being adopted by Paul.
Anyone who thinks you can use aset too design an asscher is flat out wrong.
One can not understand asschers without a very high level of understanding of virtual facets and the research is just in the beginning stages.
The effect of varying head shadow in step cuts is another area that is little understood.
The importance of patterns was ignored in the AGS asscher system yet the patterns is what separate a bad asscher from a great one.
Patterns, virtual facets, and head shadow are very hard too nail down and they go hand in hand in asschers and have effects far beyond what they do in brilliant style cuts.
I only started too understand them when I threw out the RB think and opned my eyes too what they were telling me.

Using your criteria for calling someone a master I have too call DiaGem a master of step cuts.

 

[diagem]

Date: 2/14/2008 2:28:39 PM
Author: strmrdr
Wink,
Sounds like a case of hero worship lol (had to razz ya a little)

Now some people on your list iv got a lot of respect for when it comes too rounds and too a lesser extent princess cuts but there is a very distinct gap when it comes too asschers.
The AGS asscher grading is a total failure not even being adopted by Paul.
Anyone who thinks you can use aset too design an asscher is flat out wrong.
One can not understand asschers without a very high level of understanding of virtual facets and the research is just in the beginning stages.
The effect of varying head shadow in step cuts is another area that is little understood.
The importance of patterns was ignored in the AGS asscher system yet the patterns is what separate a bad asscher from a great one.
Patterns, virtual facets, and head shadow are very hard too nail down and they go hand in hand in asschers and have effects far beyond what they do in brilliant style cuts.
I only started too understand them when I threw out the RB think and opned my eyes too what they were telling me.

Using your criteria for calling someone a master I have too call DiaGem a master of step cuts.

Thats a good one.....

Thanks..., but far..., far from it

 

[adamasgem]

Date: 2/14/2008 2:28:39 PM
Author: strmrdr
Wink,
Sounds like a case of hero worship lol (had to razz ya a little)

Now some people on your list iv got a lot of respect for when it comes too rounds and too a lesser extent princess cuts but there is a very distinct gap when it comes too asschers.
The AGS asscher grading is a total failure not even being adopted by Paul.
Anyone who thinks you can use aset too design an asscher is flat out wrong.
One can not understand asschers without a very high level of understanding of virtual facets and the research is just in the beginning stages.
The effect of varying head shadow in step cuts is another area that is little understood.
The importance of patterns was ignored in the AGS asscher system yet the patterns is what separate a bad asscher from a great one.
Patterns, virtual facets, and head shadow are very hard too nail down and they go hand in hand in asschers and have effects far beyond what they do in brilliant style cuts.
I only started too understand them when I threw out the RB think and opned my eyes too what they were telling me.

Using your criteria for calling someone a master I have too call DiaGem a master of step cuts.

Strmrdr... I haven''t had the time to look at what you call the AGS asscher grading. Thank you for playing with the options and your observations.

I DO BELIEVE that what most in the trade call an asscher cut, wouldn''t qualify in my book, per the classic definition, of a small table, high crown ideally sqaure, cut corner step cut stone that gave a wealth of fire relative to its nearest neighbor, the emerald cut.

I believe that there is constant study going on relative to improving the AGS cut systems, they are only in phase one.

 

[strmrdr]

Date: 2/14/2008 3:56:50 PM
Author: adamasgem
Strmrdr... I haven''t had the time to look at what you call the AGS asscher grading. Thank you for playing with the options and your observations.

I DO BELIEVE that what most in the trade call an asscher cut, wouldn''t qualify in my book, per the classic definition, of a small table, high crown ideally sqaure, cut corner step cut stone that gave a wealth of fire relative to its nearest neighbor, the emerald cut.

I believe that there is constant study going on relative to improving the AGS cut systems, they are only in phase one.

I agree with you that the Asscher of today is not the asscher of yesterday.
For a while I tried too use the generic name(SE) for most of today''s cuts but it led to massive confusion.
Well cut, today''s asschers are very beautiful and in their own way as much so as the old cuts.
They do lack the "attitude" of the old style.

 

[diagem]

Date: 2/14/2008 4:07:17 PM
Author: strmrdr

Date: 2/14/2008 3:56:50 PM
Author: adamasgem
Strmrdr... I haven''t had the time to look at what you call the AGS asscher grading. Thank you for playing with the options and your observations.

I DO BELIEVE that what most in the trade call an asscher cut, wouldn''t qualify in my book, per the classic definition, of a small table, high crown ideally sqaure, cut corner step cut stone that gave a wealth of fire relative to its nearest neighbor, the emerald cut.

I believe that there is constant study going on relative to improving the AGS cut systems, they are only in phase one.

I agree with you that the Asscher of today is not the asscher of yesterday.
For a while I tried too use the generic name(SE) for most of today''s cuts but it led to massive confusion.
Well cut, today''s asschers are very beautiful and in their own way as much so as the old cuts.
They do lack the ''attitude'' of the old style.

They just dont make em like they used to...

Not only the Asschers...