Highly faceted round brilliant-style diamonds

[Greentree]

As I browse through these threads I occasionally see interest in round brilliant-style diamonds that have many more facets than the 58 found in the round brilliant cut diamond. I''ve seen cuts advertised as having 90, 93, 102, and 129 facets. No doubt there are others.

I''m inclined to think these cuts are being developed as a sort of substitute for the ideal cut. Have you ever noticed how colored stones (the so-called semi-precious gems) are cut to achieve a lot of sparkle? Lots and lots of facets. This is because the stone doesn''t have a high enough index of refraction to achieve high optical performance with a low number of facets. Since this technique works for colored stones, it surely will work for diamonds too.

If high optical performance is to be achieved with a low number of facets, each of those facets must necessarily be precisely aligned with respect to each of the other facets. This is not an easy thing to achieve. It''s costly and time consuming. Indeed, if the alignment of one facet interacts with that of all the other facets, the time to accurately cut such a diamond must rise exponentially with the number of facets. I postulate that cutting a highly facetted diamond in the manner of the ideal cut round brilliant diamond is a practical impossibility. For example, if it takes three to four days to cut an EightStar diamond, it would take months, maybe years, to produce just one ideal cut highly facetted diamond.

I''m forced to conclude that these highly facetted diamonds are using a blunder-buss approach to achieve the illusion of high brilliance. That is, the facets need not be precisely aligned. There are just so many facets that no matter how you look at the gem, there''s a good chance that some facet somewhere is reflecting light. This effect is called scintillation and should not be confused with brilliance. Does anybody have a FireScope image of one of these gems? I suspect it would be a mass of tiny light leaks. Taken individually each light leak would appear small. But summed up they probably represent something significant.

 

[oldminer]

In the rush to differentiate one's product from another, the idea of adding more facets sounds like a good idea, initially. It is certain that the magic 57 facets of a round standard brilliant is not necessarily too many or too few, but somewhere in the just-about-right category for smaller diamonds of 1/4ct to 1.25ct.




Larger diamonds can use of more facets. How many more remains an unresolved question, but bigger diamonds suffer from less scintillation per square unit of measure, so more facets, properly placed, can add extra sparkle.




Too many facets make the scintillation become unresolved and too tiny.


Too few facets leave the diamond with too much large light return areas or dark zones.


It is a balancing act and it is also size and shape dependent.




Adding facets will change light behavior. Will it always make the diamond better? NO.


Could adding facets make a diamond prettier? It could, but this is not a certainty.


Do extra facets add value to a Brand? Possibly, if they mean something. Where's the proof?




I have not seen any important visual change in the appearance of 1 carat size rounds with extra facets. I have seen many poorly cut stones with extra facets that were not "special" beyond having more facets to offer. One does not wear facets. One wears jewelry or gems and while facet numbers count, the overal quality of cutting seems to play a more important role.

 

[Greentree]

I was hoping for a reply from someone who would truly know. I found your remarks about the diamond's size vs facet number to be particularly interesting. It's true. A big diamond doesn't scintillate as much as a little one. I'd noticed it before but really didn't know why.

 

[ame]

I chose the 129 facet cut because I thought it was something quite nice to look at.

 

[oldminer]

This is an imaginary representation of scintillation compared between a smaller diamond and a much larger diamond, both having the same number of facets and facet design.




In the larger stone, the amount of scintillation per square mm is far less than that found per square mm in the smaller stone.




Obviously, this is a depiction to demonstrate the point I was trying to make, not a true rendering of how any diamond scintillates.

 

[oldminer]

Here is a representation of three same size stones with an increasing number of facets. I think it demonstrates that at the upper range of high facet numbers scintillation becomes less visually pleasing and less distinct. It also demonstrates that too few facets does not have the best look, either.

 

[Rhino]

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On 9/21/2004 1:23:17 PM Greentree wrote:

As I browse through these threads I occasionally see interest in round brilliant-style diamonds that have many more facets than the 58 found in the round brilliant cut diamond. I've seen cuts advertised as having 90, 93, 102, and 129 facets. No doubt there are others.

Yes there are many. Of all the stones we've seen we are picking up 2 new lines. Not because they have more facets but what they do with those extra facets.

I'm inclined to think these cuts are being developed as a sort of substitute for the ideal cut. Have you ever noticed how colored stones (the so-called semi-precious gems) are cut to achieve a lot of sparkle? Lots and lots of facets. This is because the stone doesn't have a high enough index of refraction to achieve high optical performance with a low number of facets. Since this technique works for colored stones, it surely will work for diamonds too.

You bet it does but particularly when the manufacturers cutting the stone know what angles to cut them to.

If high optical performance is to be achieved with a low number of facets, each of those facets must necessarily be precisely aligned with respect to each of the other facets. This is not an easy thing to achieve. It's costly and time consuming. Indeed, if the alignment of one facet interacts with that of all the other facets, the time to accurately cut such a diamond must rise exponentially with the number of facets. I postulate that cutting a highly facetted diamond in the manner of the ideal cut round brilliant diamond is a practical impossibility. For example, if it takes three to four days to cut an EightStar diamond, it would take months, maybe years, to produce just one ideal cut highly facetted diamond.

While it does take a longer time to cut super ideal cuts I'm not sure I buy the 32 hours (or 3-4 days) bit. I can tell you that it is not an easy task to align 57 facets (much less 81, 91, 93, 129 etc.) but I can't imagine it being any easier or taking less time.

I'm forced to conclude that these highly facetted diamonds are using a blunder-buss approach to achieve the illusion of high brilliance. That is, the facets need not be precisely aligned. There are just so many facets that no matter how you look at the gem, there's a good chance that some facet somewhere is reflecting light.

Of the modified rounds I've been able to inspect that were not good performers, what you are saying is true to an extent however you have to keep in mind that if those facets are cut to angles that do not flatter light return within the diamond, 95 facets cut to the wrong angles will still produce a drab stone. This has been the case with many of the modified rounds I've seen.

This effect is called scintillation and should not be confused with brilliance. Does anybody have a FireScope image of one of these gems? I suspect it would be a mass of tiny light leaks. Taken individually each light leak would appear small. But summed up they probably represent something significant.
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Attached are LightScope results of one of these multifaceted stones which we are taking on called the Eighternity. 81 facets, excellent optical alignment of all the facets and they are also cut to magnificient specs within the realm of ideal cuts. I have seen some modified rounds, more than 57 facets that also have excellent 3d symmetry but the facets were not cut to angles that maximized light return within.

Note the amount of hot spots (or blacks) within this LightScope image. This contributes to some of the most amazing scintillation observable within a round brilliant cut.

 

[Rhino]

For your edification ...

Here is a virtual model of that same Eighternity. You'll need the free Gem Advisor software which you can download http://www.pricescope.com/MSU/Library/GemAdviserSetup.exe. Install it, open it up and play with the demo file so Windows will associate all .gem files with the program.

Then open up the file attached to this post and put the diamond is "disco lighting" and hit the green play button.

After you've done that open up the file in my next post which is of an H&A round. Without being here *live* to make the comparison, this is the next best thing.

Pull up both stones side by side, put em in disco light and hit the green play buttons.

 

[Rhino]

Here's an H&A round brilliant that did excellently in our optical tests.

 

[Greentree]

Interesting. So lots of scintillation is the goal of these particular cuts. You learn something new everyday.

 

[Greentree]

No less a luminary than Gabby Tolkowsky has introduced a design with 109 facets. And if Rhino is introducing two lines of them in his business, does this mean a trend has been spotted --a trend toward highly scintillating diamonds?

This bears watching. Is the marketplace on the move, or is it a flash in the pan?

 

[Rhino]

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On 9/21/2004 5:37:30 PM Greentree wrote:





No less a luminary than Gabby Tolkowsky has introduced a design with 109 facets. And if Rhino is introducing two lines of them in his business, does this mean a trend has been spotted --a trend toward highly scintillating diamonds?

This bears watching. Is the marketplace on the move, or is it a flash in the pan?
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I've pondered this same question Greentree.

I've heard critics/skeptics say that H&A would only be a flash in the pan. H&A are here to stay and IMO, as various light measuring technologies are and become available to people like myself and even more inparticular, high end cutting factories, there are factories taking advantage of these opportunities and cutting diamonds whose results are off the charts and/or cutting diamonds with optical symmetry and light return that we are not traditionally used to seeing. AND THE RESULTS ARE BEAUTIFUL to those factories who are cutting such diamonds.

In my personal opinion Greentree, these evolutions are here to stay and are not a flash in the pan so to speak. Education is the key to enlightenment and once people learn and see the results for themselves, I don't think they'll stop producing a product that will be in such high demand. I don't part with my own money too easily so if I'm going to invest tens or hundreds of thousands of our capital, it must be low risk.

Of course in the end it is you and your fiance's *eyes* that must ultimately be pleased. If you're interested and when you're ready I can ship out both cuts to you and let you decide what you like best for your fiance.

 

[niceice]

Of the round brilliant cut diamonds with extra facets that we have evaluated, it seems to us that while they display more brilliance, they exhibit less dispersion which might be why one of the more prominent brands runs their advertising campaign along the lines of "the most brilliant diamond" blah, blah, blah, but we're looking for more of a balance of brilliance and dispersion so thus far we haven't found any that put a smile on our faces... But it's really all a matter of personal preference, some people prefer more brilliance than dispersion and others prefer more dispersion than brilliance, so we suppose that there is a diamond out there for everybody and their different tastes...