seeing circle "effect" in a radiant?

[Ann]

I have been looking at radiants online and at B & M''s. Most of the stones I have viewed have this circle effect about half-way down into the stone. I don''t like this and am wondering is this normal? Some of the stones were Original Radiant Cuts. I also noticed it online at a PS vendors site. I''m hoping these are poor cuts and good things come to those who wait!

 

[Garry H (Cut Nut)]

Check out the Fish eye effect in the Tutorial

 

[valeria101]

Date: 5/23/2005 12:56:13 AM
Author:Ann

I''m hoping these are poor cuts and good things come to those who wait!

Perhaps not "poor" but that fish eye effect is not considered a merit anyway. It may not be avoidable entirely, but easy to get discrete enough so that it does not show without some special viewer (the IdealScope does exagerate even faint fish eye, IMO). If those radiants have thick girdles things get allot worse (the fish eye is a reflection of the girdle)...and there are lots of radiants with thick girdle out there. Is this the case with the stones you have seen ?

 

[RADIANTMAN]

If the "circle effect" you refer to is a white circle, then it is, in fact, a characteristic present even in well made radiants. It would not be characterized as a "fisheye" unless the circle is in the wrong place - too close to the culet. If it is too close to the culet, then certain of the pavilion angles are probably too flat, and the diamond will leak light when you tilt it even slightly. Such stones are poorly cut and should be avoided.

More likely, the circle effect you refer to is a dark circle around the culet. This is not a "fisheye." In fact, it is the opposite. A "fisheye" refers to the appearance which results from a diamond with pavilion angles which are too flat. The dark circle, if it is too severe, results from pavilion angles which are too deep. Many people prefer a stone with a slight "circle effect," since those stones tend to have a crisper, less diffuse brilliance Others prefer more of a "crushed ice" or "kaleidescope" effect. At Original Radiant, we believe that both looks, if done right, are beautiful, and it is up to the consumer to decide which he or she prefers.

If the "circle effect" bothers you, then either you have seen stones where the effect is too severe, or you are one of those who prefer the "crushed ice." look. In either case, I'm sure there is a Radiant out there you will love. Just one word of caution, Radiants are complicated, and even I, who has spent the last 20 years working almost exclusively with them, cannot fully evaluate one without seeing it live. Photos, idealscopee images, sarins, etc, are better than nothing, but they cannot assure you that the diamond will have the kind of brilliance you like, particularly since personal preference is an important part of the equation. While there is obviously such a thing as a poorly cut radiant, there are also well cut ones that you, personally, may not like as much as others.

Keep looking - your diamond - Original or not, is out there.

 

[lurker]

If you can post pictures of the two categories with their sarins, it would be most informative

 

[Diachi]

Date: 5/23/2005 12:56:13 AM
Author:Ann
I have been looking at radiants online and at B & M''s. Most of the stones I have viewed have this circle effect about half-way down into the stone. I don''t like this and am wondering is this normal? Some of the stones were Original Radiant Cuts. I also noticed it online at a PS vendors site. I''m hoping these are poor cuts and good things come to those who wait!

I''m not sure if this is what you mean, but as you probably already know, radiants are supposed to be a combination of an emerald and a brillant...in my mind, I take that as looking like a square or rectangular brilliant and so the "circle" is the table/brilliant part of the cut shining through. I don''t like the "shattered glass" look but those are also an option. Is that what you are refering too?

Oh, and my Radiant was appraised as a 1A Class Cut and IMHO, is the definition of a "square brilliant" (with the corners clipped of course)...

 

[Ann]

I don''t think what I am seeing is a fish-eye effect. Perhaps it is as Diachi describes - the round brilliant part of the cut coming through. But, as I look into a radiant, should I see facets near the top of the stone that look like step-cut(emerald) facets and then deeper into the stone see facets that resemble more of a brilliant cut? Very confusing, at least to me right now. And, how does table size and depth effect this circle look from the cut? That doesn''t make much sense, sorry!

 

[jls944]

What does this circle effect look like? Can someone posta picture? Thank you.

 

[RADIANTMAN]

Unfortunately, I don''t have the computer expertise to post pictures, etc., but the "crushed ice" is characterized by a busier life - at its most extreme form you can''t make out the individual facets at all - the life looks like a lot of little dots. The other kind of brilliance, which we at RCDC call "traditional" has a less busy life in which the individual facets are more clearly distinguishable.

Keep in mind that the two kinds of life are part of a continuum - there is something in between. The differences are only really significant at the extremes.

If someone posts a picture of a radiant with what they consider to be a "circle effect" I could probably identify for people what kind of "circle" it is.

 

[Ann]

I have not seen this stone in person, but could someone explain the circle effect in this one? The ones I have viewed in person are easily recognized as having this effect internally. I have seen some pictures that do exhibit that cracked glass look, but don''t have this circle. So, maybe it is the brilliant portion of the stone coming through. One jeweler brought in 6 stones for me, and 4 of them displayed this circle. The others I don''t remember because I dismissed them for other reasons.

 

[Ann]

Cracked glass ?

 

[Garry H (Cut Nut)]

in the one you showed it is common old garden leakage

 

[RADIANTMAN]

Anne:

I am not an expert on ideal scope images ( I could tell you more from a photo), but I suspect that the diamond would have the black circle around the culet (where the intense pink is in the ideal scope image), which is characteristic of certain of the pavilion angles being too deep. If you flattened the culet 2-3 degrees, the life would be more even and the "circle" effect would diminish or disappear. Of course, the diamond would weigh considerably less.

 

[Garry H (Cut Nut)]

Date: 5/23/2005 6:41:18 PM
Author: RADIANTMAN
Anne:

I am not an expert on ideal scope images ( I could tell you more from a photo), but I suspect that the diamond would have the black circle around the culet (where the intense pink is in the ideal scope image), which is characteristic of certain of the pavilion angles being too deep. Stan you will find the ideal-scope quite useful if you give it a try. Check out the reference chat ww.ideal-scope.com. The red will be bright and the white will be dark once the stone is set. If you flattened the culet 2-3 degrees, the life would be more even and the ''circle'' effect would diminish or disappear. Of course, the diamond would weigh considerably less.agreed

 

[diamondsbylauren]

Hi Everyone- Garry, I know you hate this, but the Ideal Scope is TOTALLY USELESS in judging the cut of a Radiant Cut Diamond.

USE YOUR EYES- don''t obscure them with pink plastic

Later!

 

[RADIANTMAN]

Hey David and Garry:

Let''s find some middle ground. In fact, I have looked at at probably 200-300 radiants through the idealscope, and while, I don''t think the info is useless, it is quite difficult to interpret. As best as I can tell, Garry''s has no sample images for radiants - he lumps them together with princesses. Since true radiants have a reflection pattern quite a bit different than princesses, I haven''t found those samples particularly helpfull in interpreting radiants. I do, however, think that, interpreted correctly, the information can be useful, if it is not possible to see the stone in person, and if you have the expertise to interpret it correctly. This presupposes that the image you''re seeing is honest, since slight variations in the technique used can completely change the image. I have little faith in computer generated images for radiants because, as far as I know, there has not been sufficient research done on the radiant to make those images reliable.

I think most people would agree that there is no substitute for seeing the stone (or buying from someone whose judgement you completely trust). If that is not possible, then more informaton is better than less, if (and this is a big if), you know what to do with it.

 

[diamondsbylauren]

How cow- another person to disagree with!!


there''s no one I respect more than Stan- but in this case, we''ll have to agree to disagree.
In my opinion the IdealScope gives NO useful info about a Radiant Cut diamond- therefore, the info it gives is meaningless, or worse.
I say this after using it to look at many stones- including a simply drop dead gorgeous 5 carat J/VS1 we had- which looked terrible thru the IdealScope, yet delicious in person.

If one has the ablity to take a IS photo, then take an unobstructed photo which is going to give a far better idea what you are looking at. The same holds true when I am holding the diamond in person- the unobstructed veiw is better, every time.

 

[RADIANTMAN]

David-We don''t disagree much (though I think I''m a little more diplomatic). Data which is more likely to be misinterpreted than interpreted correctly has value only in the right hands. The question is what is a "good" ideal scope image and what is a bad. In order to answer that question intelligently, you have to have compiled and analyzed a large database of radiants. In my opinion, at least 1000 stones would have to be analyzed before even tentative conclusions could be reached.

I''m skeptical that this research has been done. Based on my own limited informal research, I believe that I can predict some (not all) characteristics of radiant cut life based on idealscope images. I do not, however, find Garry''s princess cut examples particularly useful. While I''m sure Garry will not agree, I believe that if he were to do the research necessary to make ideal scope images useful for radiants, his concept of what is a "good" and "bad" ideal scope image would change. Even then, a "good" image would not be a guaranty of a good stone.

If cut grade of radiants, or for that matter other fancies, were as simple as looking through an idealscope, I suspect the GIA and AGS would have started issuing cut grades a long time ago, and a lot of time and money spent on researching the issue could have been saved.

 

[Garry H (Cut Nut)]

I never attempted to d this work because it is too time consuming and difficult for a 1 man band.
I did it with HCA for rounds. AGS have used an almost identical process for princess cuts to what I used for HCA and come up with a complex chart that we know will cause a huge imporvement in princess cutting.

2 years ago Peter yantzer told me they did just what you said Stan - they did indepth anaylsis on 1,000 princess cuts as they came thru the lab (using the Firescope and DiamCalc and the percursor to the new ASET scope) and put the plies of data in 10 piles along one wall, best to worst.
I am not sure what cut they will do next - but it is a very time consuming process - and they only have a result for square 5 chevron per corner (2+1+2) stones.

Radiants have the 2 extra variables - an additional pavilion structure and LxW - so it is about 100 time harder to do that way.

(David watch out - the dinasuars are starving

)

 

[RADIANTMAN]

Garry- since you agree that the research has not been done with respect to radiants (or, for that matter, any fancies other than princesses), is David wrong when he says that the idealscope shouldn't be relied on in evaluating radiants?

Date: 5/24/2005 9:34:54 PM
Author: Garry H (Cut Nut)
I never attempted to d this work because it is too time consuming and difficult for a 1 man band.
I did it with HCA for rounds. AGS have used an almost identical process for princess cuts to what I used for HCA and come up with a complex chart that we know will cause a huge imporvement in princess cutting.

2 years ago Peter yantzer told me they did just what you said Stan - they did indepth anaylsis on 1,000 princess cuts as they came thru the lab (using the Firescope and DiamCalc and the percursor to the new ASET scope) and put the plies of data in 10 piles along one wall, best to worst.
I am not sure what cut they will do next - but it is a very time consuming process - and they only have a result for square 5 chevron per corner (2+1+2) stones.

Radiants have the 2 extra variables - an additional pavilion structure and LxW - so it is about 100 time harder to do that way.

(David watch out - the dinasuars are starving

)

 

[diamondsbylauren]

Hey Garry- Starving??????
if only I could get my waist size down...... I haven''t had a carb since......well, let''s just say I''m supposed to NOT eat carbs - but I do love Shredded Wheat and oatmeal.


- I think a lot of folks woud absolutely LOVE to go to a real live Jurasic park.
One can only wish to be a dinasaur- who doesn''t LOVE dinasaurs?????


PS- none of the cutters of princess cut diamonds we know have altered anything based on the reasearch you mention.
In my experience, financial realities play the largest role when deciding how to cut a diamond.
Princess cuts allow for a greater retention of weight, and this fact is going to continue to infuence the decisions cutters make- far more than whatever study.

 

[Garry H (Cut Nut)]

Date: 5/25/2005 10:41:16 AM
Author: RADIANTMAN
Garry- since you agree that the research has not been done with respect to radiants (or, for that matter, any fancies other than princesses), is David wrong when he says that the idealscope shouldn''t be relied on in evaluating radiants?

Not at all Stan. The same principals used for rounds and princess will work for any shaped stone.

(David, you have a whole club of Dinasuar cutter friends?)

 

[Rank Amateur]

The HCA is at least objective and doesn''t make its living selling radiant cuts. And it does give a visual on light return.

What it can''t do is measure any given consumer''s "pretty" or "appealing" or "good bang for buck".

 

[RADIANTMAN]

Date: 5/25/2005 5:16:59 PM
Author: Rank Amateur
The HCA is at least objective and doesn''t make its living selling radiant cuts. And it does give a visual on light return.

What it can''t do is measure any given consumer''s ''pretty'' or ''appealing'' or ''good bang for buck''.

As I understand your post, you suggest that my opinions with respect to radiants, and the usefullness of the idealscope in analyzing them, should be dismissed because I make my living selling them. (actually, we don''t just sell them, we invented them).

I assume that you think that Garry''s opinions with respect to the idealscope and the HCA should be dismissed for the same reasons.

Personally, I believe that Garry is the most authoritative person with whom I can discuss the merits (and shortcomings) of the idealscope, notwithstanding that he "makes his living" selling them.

Can I assume from your post that you are a consumer with no economic interest in either the diamond industry or this forum? Perhaps you should make the appropriate disclosures so that we can all know to whom we are speaking, and weigh the biases that we each have.

 

[RADIANTMAN]

Date: 5/25/2005 5:08:07 PM
Author: Garry H (Cut Nut)

Date: 5/25/2005 10:41:16 AM
Author: RADIANTMAN
Garry- since you agree that the research has not been done with respect to radiants (or, for that matter, any fancies other than princesses), is David wrong when he says that the idealscope shouldn''t be relied on in evaluating radiants?

Not at all Stan. The same principals used for rounds and princess will work for any shaped stone.

(David, you have a whole club of Dinasuar cutter friends?)

The key to your point is the word "will." Until the necessary research is done, how can you be so confident that you are interpreting the data correctly? I have a great deal of respect for you, and the research that you have done with round diamonds. But "will work" after the requisite research has been done is very different than "works now, as confirmed by research." As you acknowledge, Radiants are much more complicated to evaluate than princesses. It took the AGS years to gain the cofidence to issue a cut grade for princesses. I think that we should wait until the research is in before we present opinion as fact.

If I thought the ideal scope was a useless concept for radiants, I would not have examined as many stones as I have. But if we don''t interpret the data correctly, the data is useless, and only research, which you acknowledge has not yet been done, will tell us how to properly interpret the data.

 

[Rank Amateur]

Just a consumer - a skeptical one at that.

I'd venture a guess that Garry makes his money selling Ozzies jewelry, not selling the Idealscope at $20 per. Garry wears his bias on his sleeve and doesn't even bother to spellcheck it. (Aaaarrrggghh!)

I'd venture a guess that Porsche David drives around in comes from selling something. Radiants, maybe? Not that there's anything WRONG with that. My kids always ask when I'm getting a Porsche.

A Cayenne would look quite nice in my garage. But to put down the whole red reflector principle as worthless for radiants is nonsense.

I am suspicious of all things internet - especially internet sales. That said I dropped a nice chunk of change a while back sight-unseen on a loose diamond.

 

[diamondsbylauren]

Hey RA-

I share Stan's respect for the amount of work Garry's done- regardless if I agree with the findings.
Nor would I question what his financial motive might be- this forum is about discussing people's opinions about ( on this "Rocky Talk" section at least) diamonds.


Maybe he sells a billion IdealScopes- or gets $500 every time someone clicks on the HCA- I hope he does- because, as I've said- he's worked very hard- he deserves the success he acheives.
But I am in no way suggesting Garry is arguing his point solely for financial gain, as you seem to be accusing me of doing.


I am called a dinasaur. That's fine. I was trained to grade diamonds at Harry Winston, at a time when it was the largest loose diamond company in the world. Back in the Paleothic period...heheheh

I was taught that 60/60 was the "Ideal" proportion for a round diamond- and we graded hundreds of diamonds a week. So I developed my "taste".

That was 1976 and since then I've busted my butt in this business.
If we sell a lot of diamonds- it's because of what we offer, and how we represent it- in a forthright and critical manner.
Yes, I DO love to drive a Porsche- waited 45 years to get one! I work very hard 60-80 hours a week to make sure I can keep it.

But it's not worth- no money is worth- selling out and using my experience to mislead people.

I have used the IdealScope on Radiant Cut Diamonds, and found it to be of no value.

The truth is, I state my opinion- which is an opinion I have a lot of conviction in- as does Garry.
He and I are not all that different in this regard.

 

[icelady]

Date: 5/25/2005 7:20:38 PM
Author: Rank Amateur
Just a consumer - a skeptical one at that.

I''d venture a guess that Garry makes his money selling Ozzies jewelry, not selling the Idealscope at $20 per. Garry wears his bias on his sleeve and doesn''t even bother to spellcheck it. (Aaaarrrggghh!)

I''d venture a guess that Porsche David drives around in comes from selling something. Radiants, maybe? Not that there''s anything WRONG with that. My kids always ask when I''m getting a Porsche.

A Cayenne would look quite nice in my garage. But to put down the whole red reflector principle as worthless for radiants is nonsense.

I am suspicious of all things internet - especially internet sales. That said I dropped a nice chunk of change a while back sight-unseen on a loose diamond.

RA Where are you coming from?

 

[Garry H (Cut Nut)]

Stan, you make some good points. The ideal-scope does show if there will be big localized dead patches in any shaped stone - they should be avoided. Smaller diesseminated leagake is better because it aids contrast.
The AGS ASET scope also helps by further describing the directin that light is coming from - personally i am finding it is easier to use the ideal-scope to pre screen princess cuts, and then use the ASET to look at distributions - AGS should be selling the new tool at Vegas - will you guys be there?

David, I have had many people think I was a crackpot Aussie fruitcake and HCA was bunkum etc, but gradually I have worn them down. I think there is about 3 left, Initials B&J and MG. And they are not as mentally stable as you, so you are a better callenge

 

[Nicrez]

Rank, I see where you are coming from, but trust me, these guys know their stones. Stan, if anyone would know what radiants SHOULD look like, what they COULD look like, and what they are capable of...

Just a little advice to anyone who posts, please know that the three men who have been posting to this thread have been in the industry longer than anyone here. They have accumulated knowledge FIRSTHAND, and have probably individually seen more diamonds than all us average joes combined.
A litte respect please.

We can agree to disagree, as I personally find merit in any study of cut and light performance, but agree that it takes much more research into the specifics of each cut style to determine if a test is truly viable. You wouldn''t test an emerald or baguette in an idealscope, but these stones DO have merit, even though they are leakers. Diamonds are NOT made for one cut alone, and somewhere out there is a horsehead shaped diamond just frightened of the idealscope...

Garry, David and Stan, please continue with your discussion about Radiants (it''s also somewhat entertaining), because we could benefit from anyone learning the secret of radiants, and if there is any way at all to classify and grade their brilliance...