Radiant Diamond Cut Evaluation Education

[sarahb]

Kenny - I have (twice) provided my thoughts on David's diamond#2 based on seeing the diamond in person. If you disagree with my observations based on viewing the photo and the ASET, please share your reasons. I'd be happy to address them as best I can. But continuing to play out your grievances against David by attacking his integrity is not helpful to the folks who come here to learn. I don't know the backstory that has led to your attitude toward David and perhaps you have legitimate gripes against him, but I do know that beating this dead horse is distracting from a serious, and in my opinion important conversation.

+ infinity
There are people who would like to see where this thread goes.

As a card carrying member of the peanut gallery, I can't understand the hesitancy to go thru the radiant tutorial of good-better-best, presenting the pros & cons on a multitude of ASET & stones from each category to help this community learn. Everyone has been asking/almost begging.

Rather than draw out individuals on specific dialogue, it would be better to present the stones & ASETs to the community as a whole. Then the prosumers can dialogue about their observations with David & Stan, & the community can follow along & learn.

I always go to this image as a cheat cheat for MRBs. My image is for rounds, an image for radiants may need to address components specific to that cut only.

This is what would be helpful, just across the board spectrum of ASETS & corresponding stones images so we can learn by example.

 

[Texas Leaguer]

Kenny - I have (twice) provided my thoughts on David's diamond#2 based on seeing the diamond in person. If you disagree with my observations based on viewing the photo and the ASET, please share your reasons. I'd be happy to address them as best I can. But continuing to play out your grievances against David by attacking his integrity is not helpful to the folks who come here to learn. I don't know the backstory that has led to your attitude toward David and perhaps you have legitimate gripes against him, but I do know that beating this dead horse is distracting from a serious, and in my opinion important conversation.

+ infinity
There are people who would like to see where this thread goes.

As a card carrying member of the peanut gallery, I can't understand the hesitancy to go thru the radiant tutorial of good-better-best, presenting the pros & cons on a multitude of ASET & stones from each category to help this community learn. Everyone has been asking/almost begging.

Rather than draw out individuals on specific dialogue, it would be better to present the stones & ASETs to the community as a whole. Then the prosumers can dialogue about their observations with David & Stan, & the community can follow along & learn.

I always go to this image as a cheat cheat for MRBs. My image is for rounds, an image for radiants may need to address components specific to that cut only.

This is what would be helpful, just across the board spectrum of ASETS & corresponding stones images so we can learn by example.

That would be the ideal way to do it. (At least an excellent way- maybe even triple ex). It might be alot to ask, but if I were attempting to educate on radiants, that would probably be the approach I would take. The articles I have submitted to the knowledge base here have been posted with a link to a special thread for discussion. Then the material and the discussion is archived there and can be referenced easily.

 

[Rockdiamond]

Next up is another great case study.
I'll let Stan take the first crack at this one

 

[Rockdiamond]

Kenny - I have (twice) provided my thoughts on David's diamond#2 based on seeing the diamond in person. If you disagree with my observations based on viewing the photo and the ASET, please share your reasons. I'd be happy to address them as best I can. But continuing to play out your grievances against David by attacking his integrity is not helpful to the folks who come here to learn. I don't know the backstory that has led to your attitude toward David and perhaps you have legitimate gripes against him, but I do know that beating this dead horse is distracting from a serious, and in my opinion important conversation.

+ infinity
There are people who would like to see where this thread goes.

As a card carrying member of the peanut gallery, I can't understand the hesitancy to go thru the radiant tutorial of good-better-best, presenting the pros & cons on a multitude of ASET & stones from each category to help this community learn. Everyone has been asking/almost begging.

Rather than draw out individuals on specific dialogue, it would be better to present the stones & ASETs to the community as a whole. Then the prosumers can dialogue about their observations with David & Stan, & the community can follow along & learn.

I always go to this image as a cheat cheat for MRBs. My image is for rounds, an image for radiants may need to address components specific to that cut only.

This is what would be helpful, just across the board spectrum of ASETS & corresponding stones images so we can learn by example.

Thank you Sarahb- that was a great post.
Here's the challenges we face in making such a chart for Radiant Cuts.
First, is taste.
Here's where we really have a totally different set of considerations as compared to round.
Buyers of Radiant Cuts ( and other fancy shapes) are faced with far more in the way of choices.
For a Radiant in particular:
does one want Square, or rectangular?
Small corners or large?
Smaller, more numerous reflections, or bolder ones.
So we'd need charts for all those to help the type of people who choose fancy shapes in the first place. They want something different. And since there's so many variations, there's going to be a lot of different desires- does that make sense?

Bryan- a grading system that might be effective would be one where there's a few key aspects, each with a score.
This might remove the subjective aspect of the grade so that buyers can use their own desires to select.
Spread
Contrast
Brightness
Even-ness

A few potential aspects that might be scored.

 

[pyramid]

What Pricescope is or has been in the past is all about top cut, to the extent it is geeky. To maximise the look of the diamond even with low color or clarity. I think what Diamonds by Lauren are doing is diamonds which look good but are not top cut radiants by design. This is like two different products here trying to discuss the same thing and it means something different to each.

I am reminded of a board a came upon one time on the internet about graphic equalizers, I like to listen to music but the people there were talking about £20000 graphic equalizers and how every minute detail sounded different and what was correct and what was not. Well cut diamonds remind me of this. Or the class in Art where we were told that a top quality camera would cost about £11000. This is an elite topic, the cut is king but it is being set alongside diamonds where the other two Cs are lower. Diamonds are about beauty otherwise there may be other theories where boards are discussing Color is king or Clarity is king. e.g. taking clarity down to 100x magnification instead of 10x.

Diamonds by Lauren have a different approach to diamonds. I would like to learn though what makes a top radiant cut, one which looks like a super ideal round under the asset compared to what is a really bad radiant cut. This is what people who are picky and want the cut is king want to see in a radiant cut, the ones who like to dissect every little thing, like the graphic equalizer people.

 

[pyramid]

Reading David's last post, it seems they are geeky too. So come on let us see the different flavours, because some people like myself don't know them. Show the squares and the rectangles, large sparkles, small sparkles, bold reflections, show us the other categories of brightness, how even the light return is, and how they score, how we can check their score over the internet, not just from someones mouth. Can this even be done or can they only be bought in person? We want to learn. I would love for radiant cut to be as well liked as other fancy cuts on Pricescope.

Where are the sellers of diamond pears only or ovals? They are not competing with ideal cuts!!!

 

[Rockdiamond]

Reading David's last post, it seems they are geeky too. So come on let us see the different flavours, because some people like myself don't know them. Show the squares and the rectangles, large sparkles, small sparkles, bold reflections, show us the other categories of brightness, how even the light return is, and how they score, how we can check their score over the internet, not just from someones mouth. Can this even be done or can they only be bought in person? We want to learn. I would love for radiant cut to be as well liked as other fancy cuts on Pricescope.

Where are the sellers of diamond pears only or ovals? They are not competing with ideal cuts!!!

Aw shucks, that's a very nice compliment Pyramid!

IMO, when it comes to evaluating the cut, a lot of what is true for radiant cuts, is also true for pear shapes, ovals and cushion modified brilliants.

 

[Gypsy]

IMO, when it comes to evaluating the cut, a lot of what is true for radiant cuts, is also true for pear shapes, ovals and cushion modified brilliants.

Disagree. Heartily disagree. Most Cushions, pears and ovals can be optimized. And they look BETTER with bright red ASETs to the naked eye. Standard radiants (not modified), I am willing to concede MAY be an exception and NEED a bit more leakage And maybe cushions with the same facet structure as radiants.

But you haven't proven that hypothesis of yours yet.

In order for your tutorial hypothesis to have validity you need to show how stones with more leakage in the ASET are more pleasing to the naked eye than stones without that leakage.

Which means despite your rhetoric about corners and ratios you NEED to post some radiants with ASETs that show consistent brightness and little to no leakage and PROVE that they are actual INFERIOR to the naked than than those with leaky ASETs.

This isn't me trying to "distract" you. And it was the entire point of my second post in this thread.

And still you have not done it.

 

[Rockdiamond]

I appreciate your questions Gypsy, thanks for putting it in a form I can digest.

I get it that you feel that a stone optimized for light performance is better than a stone optimized for sparkle and spread.
Many people feel that it's different, as opposed to better.


About leakage: my position is not that "more" leakage is better.
The leakage needs to be properly dispersed around the stone.
I'm not a light scientist like Karl- and a few select others who understand ray tracing. When the light bounces around inside the diamond, analyzing it becomes exponentially more complicated.
I'm also not a cutter, so I can't explain the technicalities of how it works regarding the angles and so on.
I'm hoping others will chime in to give whatever clarity possible to this aspect

I'm a guy who loves diamonds, and gets to buy a lot of them- and set them.
So on a given modified style stone I can see a fair amount of white dispersed around the aset-then I look at the diamond. BAM. Tremendous life throughout.
Then, if set properly, stones like this that preform tremendously well.
Therefore, based on the physical evidence proved by ASET, I can show that the right amount of leakage is extremely beneficial to stones that are cut for sparkle and spread. I'm not the only person who loves stones cut to the modified brilliant style
Far from it.
I am not saying it's wrong to give up spread for light performance.
I can totally appreciate and love LP stones. I'm quite familiar with them as well.
It's also not "wrong" to give up a little brilliance for a lot of spread.
Just different.
Peace

 

[FrekeChild]

Can someone please just tell me what makes a good radiant? I thought that was the point of the thread, and yet, three pages in, there are like 5 images, and one is a chart of rounds posted by a consumer!!

I am tired of seeing monologues! I want to see pictures!!

Is there some kind of universal guide to types of radiants? what makes a radiant different from a cushion/princess/other shapes? why are certain types more desirable than the others?

 

[sarahb]

Can someone please just tell me what makes a good radiant? I thought that was the point of the thread, and yet, three pages in, there are like 5 images, and one is a chart of rounds posted by a consumer!!

I am tired of seeing monologues! I want to see pictures!!

Is there some kind of universal guide to types of radiants? what makes a radiant different from a cushion/princess/other shapes? why are certain types more desirable than the others?

Freke, we're just waiting for the horse to drink...

 

[Rockdiamond]

Can someone please just tell me what makes a good radiant? I thought that was the point of the thread, and yet, three pages in, there are like 5 images, and one is a chart of rounds posted by a consumer!!

I am tired of seeing monologues! I want to see pictures!!

Is there some kind of universal guide to types of radiants? what makes a radiant different from a cushion/princess/other shapes? why are certain types more desirable than the others?

Freke- part of the potential value of this thread is a bit of crowd sourcing.
As opposed to telling people "what's the best radiant", an open discussion can flush out what people who love the shape want to see.
Here's a stone we've brought into the discussion.I realize it's based on limited info, but what is your impression of it?

 

[RADIANTMAN]

Can someone please just tell me what makes a good radiant? I thought that was the point of the thread, and yet, three pages in, there are like 5 images, and one is a chart of rounds posted by a consumer!!

I am tired of seeing monologues! I want to see pictures!!

Is there some kind of universal guide to types of radiants? what makes a radiant different from a cushion/princess/other shapes? why are certain types more desirable than the others?

No there is not (that I know of at this time) some kind of a universal ASET guide and that's the point of the discussion. Perhaps its possible to develop a radiant chart that would help people better understand from an ASET what a live radiant would look like. The discussion here could serve to help us create one.

Every diamond shape is different. People readily understand that emerald cuts are not supposed to reflect light the way a round does, and I have never seen anyone assert that they are somehow poorly cut because they are different. A well cut round is a round that spreads its size and reflects light the way a round is supposed to. A well cut emerald cut is one that spreads its size and reflects light the way an emerald cut is supposed to. And the same is true for a radiant cut and every other shape.

David has now posted 3 pictures. Each has a different ASET signature, and each reflects light a little differently when seen live. All three diamonds, including #2, are extremely attractive and would be considered excellent cuts by the trade. Individual consumers seeing all three would likely vary in which look they prefer. The difference between any of these diamonds and a poorly cut radiant would be readily apparent when compared side by side since the visual differences in cut of radiants (actually in fancies in general) is far more obvious to the untrained eye than it is in rounds. The reason why so many poorly cut radiants are out there is not because the uneducated consumer can't tell the difference without a technological tool like an ASET. Its because they don't have the opportunity to see the diamonds side by side.

David - can you post another example of a well cut rectangle - ideally one with a slightly different flavor, and then the four "good' ASETs side by side? It would be interesting to see what they have in common and how they differ. Then we could compare the ASETs to some poor cuts and see if a pattern emerges and together maybe we could create the chart that people want to see.

The exercise requires believing that David and I are accurately describing what the diamonds look like live and that the radiants we say are well cut are well cut. Those who believe that we are lying conniving thieves looking to foist inferior diamonds on unsuspecting consumers will never be convinced nor will those who think that a radiant simply "ought" to have an ASET signature as close as possible to an ideal cut round no matter what the actual diamond looks like.

 

[petrock<3]

Woo hoo! Can't wait to see several examples to compare.

I don't want to clog up the thread but I mentioned this in the last thread and maybe it bears repeating here.

I am trusting the photography because I have seen in person rings and diamonds that David has photographed and they were accurately represented. I picked them out to see not him.

I hope that helps.

 

[Karl_K]

Here's a stone we've brought into the discussion.I realize it's based on limited info, but what is your impression of it?

I am seeing a lot more dark zones in this one than the other 2.

 

[RADIANTMAN]

Okay this is my take on diamond #2
- good and bad -

Good -

1. Huge for its carat weight. The LXW of most 5 carat radiant is 90-95. On this diamond its 103. I did a rapnet search for radiants weighing 5.5 - 5.6 and this diamond looks bigger than more than 1/2 of them.

2. Beautiful even brilliance when viewed straight on. No concentrations of black or windowing. From a direct angle the brilliance holds its own against any radiant

Bad

1. Windows out a bit- but not too much - with relatively little tilt

2. Will likely lose its brilliance pretty readily when the pavilion gets dirty. It will be important for its ultimate wearer to keep it really clean and should be mounted in a ring style that makes it easy to clean

That's instructive commentary Stan. Is there anything in either the ASET image or the photos that would give a clue to the tilt issue?

Can you also give your commentary on diamond #1?

Hi Bryan - sorry I missed this post in the morass

I don't know how to pick up and judge the extent of the tilt issue (which on this diamond I consider pretty minor) from the ASET. That's part of why I'm hesitant to rely too much on ASET. Perhaps you need to use multiple images from different angles. But from the image usually shown I personally don't know how to identify it.

Diamond #1 is a great example of a beautiful well cut rectangle. From a cutting standpoint, it is very difficult to minimize/eliminate the bowtie effect on a long stone and the presence of a significant bowtie is probably the most common defect (other than lumpiness which is a problem all shaped radiants) in rectangular radiants. Unlike a circle or a square, the rectangular shape is not geometrically symmetrical and creating optical symmetry in an asymmetrical shape is a true challenge, particularly as the rectangle gets longer.

It is important to note that bowties are NOT from leakage and will generally appear red on an ASET but the fact that they are red doesn't stop them from being a characteristic that consumers don't like.

Diamond #1 is a great example of how even in a long rectangle the bowtie can be minimized to the point of irrelevance in the hands of the right cutter.

 

[Rockdiamond]

Petrock, will you marry me?
JOKING!!!
Seriously, thank you.

Karl- are you seeing dark zones in the photos or ASET?
And Karl, I won't ask you to marry me, but I very much appreciate your input.

 

[RADIANTMAN]

Here's a stone we've brought into the discussion.I realize it's based on limited info, but what is your impression of it?

I am seeing a lot more dark zones in this one than the other 2.

Karl - If by dark zones you mean concentrations of black I can tell you that the diamond doesn't have any. The life is extremely even when viewed straight on. The only issue that I see with the appearance of the diamond is the tilt issue I referenced above.

 

[Rockdiamond]

Karl,
As I already mentioned- I agree with Stan that I don't see any large dark concentrations in stone #2 looking in person.
Is it possible that ray tracing can somehow give us more clues as to why you see indications of dark areas, that don't manifest themselves in real life?

Also I did obtain a stone that Stan and I agree is not well cut.
Stan and I have slightly different ideas about that, but I will post more pics and asets this evening.

 

[Texas Leaguer]

Okay this is my take on diamond #2
- good and bad -

Good -

1. Huge for its carat weight. The LXW of most 5 carat radiant is 90-95. On this diamond its 103. I did a rapnet search for radiants weighing 5.5 - 5.6 and this diamond looks bigger than more than 1/2 of them.

2. Beautiful even brilliance when viewed straight on. No concentrations of black or windowing. From a direct angle the brilliance holds its own against any radiant

Bad

1. Windows out a bit- but not too much - with relatively little tilt

2. Will likely lose its brilliance pretty readily when the pavilion gets dirty. It will be important for its ultimate wearer to keep it really clean and should be mounted in a ring style that makes it easy to clean

That's instructive commentary Stan. Is there anything in either the ASET image or the photos that would give a clue to the tilt issue?

Can you also give your commentary on diamond #1?

Hi Bryan - sorry I missed this post in the morass

I don't know how to pick up and judge the extent of the tilt issue (which on this diamond I consider pretty minor) from the ASET. That's part of why I'm hesitant to rely too much on ASET. Perhaps you need to use multiple images from different angles. But from the image usually shown I personally don't know how to identify it.

Diamond #1 is a great example of a beautiful well cut rectangle. From a cutting standpoint, it is very difficult to minimize/eliminate the bowtie effect on a long stone and the presence of a significant bowtie is probably the most common defect (other than lumpiness which is a problem all shaped radiants) in rectangular radiants. Unlike a circle or a square, the rectangular shape is not geometrically symmetrical and creating optical symmetry in an asymmetrical shape is a true challenge, particularly as the rectangle gets longer.

It is important to note that bowties are NOT from leakage and will generally appear red on an ASET but the fact that they are red doesn't stop them from being a characteristic that consumers don't like.

Diamond #1 is a great example of how even in a long rectangle the bowtie can be minimized to the point of irrelevance in the hands of the right cutter.

Thanks Stan. Good commentary. It would be very interesting to see an example of a radiant with a bow tie and a corresponding ASET where the problem can be identified by the red.

Also, I did not see an answer to my question about optimal and/or minimum size for a radiant, given that the life derives from a multiplicity of small virtual facets. I think that would be helpful info for a prosumer.

 

[Rockdiamond]

Bryan- on the NY market, we find that in stones below .25ct: there are far more princess cuts than radiant cuts- although there are nicely cut radiants down to below .10ct.
I've seen .08ct stones
Personally I think well cut smaller stones can have good life.
But I look for different aspects in a smaller stone- say for a bracelet.



The questions about other shapes led me to thinking about how we have radiant cuts to begin with.
For those unfamiliar with the story, here's Cliff notes on Radiant History ( Stan will of course correct me)
Henry Grossbard invented the Radiant cut in the late 1970 by modifying an Emerald Cut into a modified Brilliant- the Radiant Cut
Henry applied for and was granted a patent.
Other cutters copied the design.
Henry sued.
Henry won.
Henry decided to "open source" his design

In thinking about Pear and Cushion diamonds, I realized that Henry's design- and his releasing the design to open source- is the foundation behind Pear and Cushion Modified Brilliant diamonds of today.
Cool stuff.

 

[Karl_K]

Karl,
As I already mentioned- I agree with Stan that I don't see any large dark concentrations in stone #2 looking in person.
Is it possible that ray tracing can somehow give us more clues as to why you see indications of dark areas, that don't manifest themselves in real life?

I thought it was a new stone...
The most logical answer is size and distance. It blends in small scale compared to 3 inch photos.

 

[Rockdiamond]

That's an amazing point Karl!
We're adding a variable.
Distance.
Totally makes sense that the "modified" method of moving light through the stone, creating more bounces, would necessarily mean that the variation in light return will be influenced by distance to the eye.
AMAZING- I Just did an experiment- crude, but it may mean something.
I held a Radiant cut up very close to my eye- as close as I could, yet still focus.
I saw fire! ( as defined by AGS)
From arms length, there may have been fire, but my eye could not perceive it because even the subtle moment of my arm is multiplied by the distance from my eye. Or maybe it's because the eye can't focus on such a small reflection from any distance greater than a few inches.
This discussion has really made me consider aspects of cut evaluation I never did before.


I've taken more aset pics.
Working on the corresponding pictures to go with the aset

Let's call this #4- IMO the leakage indicated by the ASET indeed is not something I like to see. There's way too much in the way of concentration and it really does manifest more on one side than the other. This is one of the stones both Stan and I agree would be considered badly cut.

 

[Karl_K]

That's an amazing point Karl!
We're adding a variable.
Distance.
Totally makes sense that the "modified" method of moving light through the stone, creating more bounces, would necessarily mean that the variation in light return will be influenced by distance to the eye.
AMAZING- I Just did an experiment- crude, but it may mean something.
I held a Radiant cut up very close to my eye- as close as I could, yet still focus.
I saw fire! ( as defined by AGS)
From arms length, there may have been fire, but my eye could not perceive it because even the subtle moment of my arm is multiplied by the distance from my eye. Or maybe it's because the eye can't focus on such a small reflection from any distance greater than a few inches.
This discussion has really made me consider aspects of cut evaluation I never did before.

Distance is always a consideration when evaluating cut both IS and ASET concentrate on close in viewing.
The distance in a RB determines how much contrast it has because obstruction is greatly influenced by distance.
With a stone that uses primarily leakage for contrast obstruction is not a huge factor but distance still effects blending and how acutely the eye can focus to see subtle shading.
It however will effect the overall brightness perception of the stone at any distance.
Contrast is strange with diamonds, some makes the stone look brighter and too much makes it darker and it varies greatly with distance. Up close internal contrast in the diamond is more important and at a distance contrast against the hand is more important, 1/2 arm length for many people is a good approximation of when the change over happens. It is what I use in my design work.

There are a lot of possible explanations on why you saw fire close and not at a distance without knowing more it is hard to say.

 

[Karl_K]

Let's call this #4- IMO the leakage indicated by the ASET indeed is not something I like to see. There's way too much in the way of concentration and it really does manifest more on one side than the other. This is one of the stones both Stan and I agree would be considered badly cut.

large continues leakage zones are usually bad news in any style of cut.

 

[Rockdiamond]

Yes, this is really a clear cut case.
Any of our prosumers would have flagged this stone on either aset or photography

 

[FrekeChild]

Nope nope nope.

 

[RADIANTMAN]

Let's call this #4- IMO the leakage indicated by the ASET indeed is not something I like to see. There's way too much in the way of concentration and it really does manifest more on one side than the other. This is one of the stones both Stan and I agree would be considered badly cut.

large continues leakage zones are usually bad news in any style of cut.

What's interesting about this diamond is that it's dead in the center but really has quite a bit of brilliance around the rest of the diamond. Unfortunately the intensity of the brilliant zones serve to make the dead zone in the middle more obvious.

In my opinion this is why evenness (is that a word?) of life is actually more important than intensity. The elements creating contrast must be distributed evenly throughout the diamond.

 

[Texas Leaguer]

Let's call this #4- IMO the leakage indicated by the ASET indeed is not something I like to see. There's way too much in the way of concentration and it really does manifest more on one side than the other. This is one of the stones both Stan and I agree would be considered badly cut.

large continues leakage zones are usually bad news in any style of cut.

What's interesting about this diamond is that it's dead in the center but really has quite a bit of brilliance around the rest of the diamond. Unfortunately the intensity of the brilliant zones serve to make the dead zone in the middle more obvious.

In my opinion this is why evenness (is that a word?) of life is actually more important than intensity. The elements creating contrast must be distributed evenly throughout the diamond.

Stan, I am getting confused now. It looks like there are now multiple ASETs being posted for the same stone and I am not sure which is which. You say that this stone is "dead in the center". Where is the corresponding photo to illustrate that? From the ASET it should be returning plenty of light from the center. Presumably that is your point - that ASET cannot be trusted to reveal this defect. But let's see correlated photo evidence to illustrate that.

For this to be constructive there must be a consistent way of presenting each example.

 

[RADIANTMAN]

Okay this is my take on diamond #2
- good and bad -

Good -

1. Huge for its carat weight. The LXW of most 5 carat radiant is 90-95. On this diamond its 103. I did a rapnet search for radiants weighing 5.5 - 5.6 and this diamond looks bigger than more than 1/2 of them.

2. Beautiful even brilliance when viewed straight on. No concentrations of black or windowing. From a direct angle the brilliance holds its own against any radiant

Bad

1. Windows out a bit- but not too much - with relatively little tilt

2. Will likely lose its brilliance pretty readily when the pavilion gets dirty. It will be important for its ultimate wearer to keep it really clean and should be mounted in a ring style that makes it easy to clean

That's instructive commentary Stan. Is there anything in either the ASET image or the photos that would give a clue to the tilt issue?

Can you also give your commentary on diamond #1?

Hi Bryan - sorry I missed this post in the morass

I don't know how to pick up and judge the extent of the tilt issue (which on this diamond I consider pretty minor) from the ASET. That's part of why I'm hesitant to rely too much on ASET. Perhaps you need to use multiple images from different angles. But from the image usually shown I personally don't know how to identify it.

Diamond #1 is a great example of a beautiful well cut rectangle. From a cutting standpoint, it is very difficult to minimize/eliminate the bowtie effect on a long stone and the presence of a significant bowtie is probably the most common defect (other than lumpiness which is a problem all shaped radiants) in rectangular radiants. Unlike a circle or a square, the rectangular shape is not geometrically symmetrical and creating optical symmetry in an asymmetrical shape is a true challenge, particularly as the rectangle gets longer.

It is important to note that bowties are NOT from leakage and will generally appear red on an ASET but the fact that they are red doesn't stop them from being a characteristic that consumers don't like.

Diamond #1 is a great example of how even in a long rectangle the bowtie can be minimized to the point of irrelevance in the hands of the right cutter.

Thanks Stan. Good commentary. It would be very interesting to see an example of a radiant with a bow tie and a corresponding ASET where the problem can be identified by the red.

Also, I did not see an answer to my question about optimal and/or minimum size for a radiant, given that the life derives from a multiplicity of small virtual facets. I think that would be helpful info for a prosumer.

Bryan - the point about diamond size is a good one. Many people who like round brilliants in "normal" sizes don't like them when they get really big because the flashes get too big and they "look like headlights." Conversely, many people who don't like "crushed ice" - still hate that term but don't know how else to shorthand the thought - in small diamonds love the look in larger ones. It's really a matter of taste but I absolutely agree that an individual's preference for small vs large flashes can change as the diamond gets smaller or larger.