Firey stones

[Upgradable]

Can anyone confirm my approach or redirect it?

If I''m looking for an ideal stone that has lots of fire, I know that I want a crown angle 35% or above. Do I then keep to pavilion angles that are on the lower edge of ideal to compensate for the high crown angle?

I''m currently looking at a stone with these parameters: 1.36 carats, depth 61.3%, table 56%, crown angle 35.0 degrees, crown % 15.0, pavilion angle 40.6 degrees, pavilion % 42.5, girdle thin to medium faceted, no culet.

I''d appreciate some examples, or at least suggested numbers to look for.

 

[quaeritur]

I have a small stone with 35 degree crown and 40.7 degree pavilion that is very firey and beautiful. I don't exactly remember the total depth, I think it's 60.7 or so, and the table is 57%.




You're on the right track, as far as my experience goes, and the stone you mention sounds great. The only other thing you might want to look for is a smaller table. 53-54% tends to give even greater fire. But it's really hard to find stones that fit all of those parameters!

 

[oldminer]

I think you are doing it right. If you want a prediction of high fire content you probably are looking at the FIC rating of the HCA system. Really, I think "ideal" cut does not extend past 35 degrees (35.1), but that is my opinion. There are really no facts to back this up, but at some point there will be a drop off in some aspect of the diamond below what some would call "ideal".




In the learning I have gone through, I find fire is not a main component of appearance in ideal cut diamond. Fire is a variable that can be measured, but it isn't all that important, to me, in the overall quality or appearance of diamond as a gem material. There are other gem materials with much more fire than any found in diamond, but they are hardly diamond-like in appearance. Fire seems to come into a diamond more as a distraction than a plus factor. You may want to get a tiny increment more fire and that's okay with me, but I am certain that if you got a lot, you would not like the stone as it would not look like a diamond should look.




Hope I didn't confuse you further.....This is a difficult subject. We often say that more equals better, when the truth is that the best diamonds are found with a high yet balanced level of brilliancy, scintillation and intensity. Fire is a fourth component of this, but again, I don't think it is one that has a great meaning in the quest for a great diamond. Maybe now, someone else will chime in with a totally different opinion.

 

[Dancing Fire]

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On 10/7/2004 2:46:56 PM oldminer wrote:


I think you are doing it right. If you want a prediction of high fire content you probably are looking at the FIC rating of the HCA system. Really, I think 'ideal' cut does not extend past 35 degrees (35.1), but that is my opinion. There are really no facts to back this up, but at some point there will be a drop off in some aspect of the diamond below what some would call 'ideal'.


In the learning I have gone through, I find fire is not a main component of appearance in ideal cut diamond. Fire is a variable that can be measured, but it isn't all that important, to me, in the overall quality or appearance of diamond as a gem material. There are other gem materials with much more fire than any found in diamond, but they are hardly diamond-like in appearance. Fire seems to come into a diamond more as a distraction than a plus factor. You may want to get a tiny increment more fire and that's okay with me, but I am certain that if you got a lot, you would not like the stone as it would not look like a diamond should look.


Hope I didn't confuse you further.....This is a difficult subject. We often say that more equals better, when the truth is that the best diamonds are found with a high yet balanced level of brilliancy, scintillation and intensity. Fire is a fourth component of this, but again, I don't think it is one that has a great meaning in the quest for a great diamond. Maybe now, someone else will chime in with a totally different opinion.
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dave
i know what you try to say,but did you ever hearing somebody complain about their stone having too much FIRE ?

 

[Garry H (Cut Nut)]

This stone has a crown angle of more than 39 degrees and it also has quite respectable light return.

 

[Garry H (Cut Nut)]

/idealbb/files/39.22IS.jpg


Here is its ideal-scope Diamcalc image.


Light return is 5 or 6% less than Tolkowsky - so not too shabby

 

[Garry H (Cut Nut)]

And just because I know someone is going to say "but it has a pale center - the ring of death"




The greatest amount of leakage is 20% (about half as much again as an 8* in the same region).




But note the small AGS type new possible table size and very high crown, and a 8% smaller spread than desirable, this stone would look very nice - and even though the spread is small - can you see how it would 'stick out' of a setting and look huge from the side view?




BTW hCA scores badly on spread - but would be around 1 without the spread factor.

 

[oldminer]

Garry: No one has ever complained to me about too much fire. Fire is not all that strong a component of diamond. THis is an inherent fact. Too much fire, such as in synthetic rutile or strontium titanate, is certainly a distraction and greater than diamond can provide. This is what I neant that too much is a detractor of brilliancy, scintillation and intensity. Fire in other coloress, diamond-like gemstones can be a distraction. I don't think fire in a diamond rises to that level by the very nature of diamond itself..... I think it is a measureable component, but not important.

However, if one wants to get a firey diamond, then why not? I can't imagine fire rising to the level of a problem in diamond. Hope this cealrs up the lack of communication on this.

 

[Garry H (Cut Nut)]

As you know OLDMINER many oldminers have heaps of it - some have far more than most modern stones.

But you are right - and even clean CZ has more than diamond.
I have a 9mm CZ on my desk - and it has too much fire - but it lacks a certain crispness and brightness (icy hardness). I know what you mean. Maybe it is because of our experiance? maybe others do not see what we see with our "expert blindness"?