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diamatuer

Rough_Rock
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I am a big fan of the HCA. It was an invaluable tool in selecting my fiance''s stone, which happens to be stunning.

Having read about various criticisms, some more fair than others (e.g., focusing on the major facets), I have not read too much about the relative weightings of brilliance, fire, scintillation and spread - other than it being based on Gary''s preferences. For the most part I agree with them, but for one difference: I enjoy fire a good deal more than scintillation. Therefore, in my world, I would change the weightings to the following:
Brilliance: 0-4
Fire: 0-3
Spread: 0-2
Scintillation: 0-1
Total: 0-10

Just food for thought.. Does anyone else agree?
 

diamatuer

Rough_Rock
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----------------
On 2/13/2003 12:45:27 PM Cut Nut wrote:

Hi D

You game to define scintillation?
----------------
Uhh, okay. I know it when I see, I just can't describe it. I would describe it as "flicker". A flash then dark then a flash.. Trouble is, if I understand it correctly, it is more linked to fire than it is to brilliance. Correct? i.e., they are both components of dispersion. Anyway, all I am saying is that I enjoy the flashes of colored light more than anything else. If there is any way to weight that more then that, that is what I would vote for.
 

Garry H (Cut Nut)

Super_Ideal_Rock
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Thats a good start Diamatuer, keep going - find the best words you can to define Scintillation, both from a static face up view, and also the movement kind.

This is SOOOO hard to do, but it would help me if you will try


We use these terms B,F and Scint all the time, but they are actually hard to define.

I like fire too, but the problem is fire can be acheived at the expense of light return - are you prepared for that trade off? And what impact does scintillation have on the other 2?
 

canadianice

Rough_Rock
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Scintillation is like a digital switch in the diamond, in a way... on/off, on/off... the others are more analog-like in that there is a graduated effect of light and fire.
 

canadianice

Rough_Rock
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I'm simply a product of my PlayStation years...

We may need a physicist in here (I am but a mere biologist!) but I think of scintillation as a twinkling effect, so if you slow-frame capture a diamond's reflection of light (can this be done with a strobe-light or would that be counter-productive? hmmmm...) then scintillation, in my mind, would have this result: returned light would be extraordinarily dynamic and bright flashes would appear on some facets but not others (and maybe simply certain portions of facets instead of the entire facet), then completely disappear from the "lit" facet (an all-or-none principle, thus "digital"), concomitant with another facet being illuminated, and this effect would move fluidly across the face of the diamond as it itself moves too.

This theory would also involve slight variations in the grain, texture or imperfection of a facet, because slight variations would prevent the eye from detecting a flash in some cases, or cause a flash in others. So then - are better polished (ie. ID/EX) more or less scintillant?

This must be an interplay of light reflection and refraction at critical angles within the diamond.
 

Garry H (Cut Nut)

Super_Ideal_Rock
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sound good Canadaice - could be simplified to "sparkle"

things that sparkle are brighter than brighter things that do not sparkle - eg silver paint is brighter than white paint - even though white returns more light.

Are you beginning to see how complex this feild of study is?
 

canadianice

Rough_Rock
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Sparkle it is!

This is definitely a complex and engrossing field. It tweaks my scientist brain... and my wallet.
 

Rhino

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Hey buddy!

Gary ... I don't believe the words "static" and "scintillation" can be used in the same definition. If we are to understand scintillation according to how it is traditionally defined, "static scintillation" is an oxymoron.

Scintillation involves the movement of light observed within the diamond. Some people describe it as the "sparkle effect", some of my clients have described it as like "looking at tinsel on a Christmas tree", "a lit fuse", "the sizzle factor", etc.

That movement can be of the light source, the observer, the diamond or all 3. It is the amount of "sparks" we see as that movement is taking place. IT INVOLVES ACTION.
That is what I love about diamonds with exceptional scintillation. They are exciting. :D

If all 3 objects were static (the diamond, the observer & the light source) there would be NO scintillation to observe. There must be movement.

Rhino
 

canadianice

Rough_Rock
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Feb 4, 2003
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Definitely, something has to be moving for scintillation to occur...

Now, here's a question (assuming Cut Nut subscribes to the credibility of Brilliance Scope readings -- I know Rhino is an enthusiast):

If you had to put two readings from the B'Scope Very High, and one "merely" High, which one is the most dispensable in your opinion (White Light; Coloured Light; Scintillation)?
 

Garry H (Cut Nut)

Super_Ideal_Rock
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What I called static scintillation is described by MSU as 'contrast'.

Don't you just hate it when folk who can not speak english are better at it than you what can only speak english!!!

CI of all three scores, I am least happy with the scintillation score on brilliancescope. It is a measure of something, but I have never been able to work out what.

You need to start reading some more off the mSU www.cutstudy.com to advance from here
 
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