yellow diamonds and fire

[Garry H (Cut Nut)]

Date: 9/8/2006 8:01:48 PM
Author: Cehrabehra
here''s another pic... seems like green is more common!

Cehrabehra did you read a thread the other day where we explained the real reason why people see less fire whith their glass / specs on?

When you photograph out of focus fire you will see much better specturms.

But our eyes at normal viewing distances do not see like that (unless you bring the diamond up to an inch or so from your eye and then you can see what you have photographed.).

Try sitting with arms still on a desk and fixing in 1 position and then count the flashes from a normal viewing distance

 

[Garry H (Cut Nut)]

Date: 9/8/2006 8:10:18 PM
Author: Cehrabehra
Okay this is from that last pic, just a little piece of it toward the middle left... and it describes what I think garry was saying about white drowning out green?

Yes, exaclty C

this is the other thread that also is relevant to this one
https://www.pricescope.com/community/threads/new-eyeglasses-anti-reflective-coating-is-sapping-out-my-diamonds-fire.50457/
» New eyeglasses - anti-reflective coating is sapping out my diamond''s fire!

 

[Cehrabehra]

Date: 9/8/2006 8:12:58 PM
Author: Garry H (Cut Nut)

Date: 9/8/2006 8:01:48 PM
Author: Cehrabehra
here''s another pic... seems like green is more common!

Cehrabehra did you read a thread the other day where we explained the real reason why people see less fire whith their glass / specs on?

When you photograph out of focus fire you will see much better specturms.

But our eyes at normal viewing distances do not see like that (unless you bring the diamond up to an inch or so from your eye and then you can see what you have photographed.).

Try sitting with arms still on a desk and fixing in 1 position and then count the flashes from a normal viewing distance

Nope, didn''t see that thread... oh wait I think I caught the first post, someone had new glasses?

oh and I don''t try to photo out of focus, the camera just auto focuses on the colors hehehe I don''t have a good camera, it sucks, but that is also what I see with my eyes... I see those same little thousands of flashes of colored light, they just aren''t frozen in time. And I don''t bring it an inch, I can see that pinfire from about 8-10 inches. The closer the better, that''s true... but I can''t even focus on the diamond at an inch. Granted this is pretty big diamond, if it was a 1 carat or smaller I wouldn''t see anything remotely like this I think.

so count the flashes at arms length on *one* of the facets? Do you want it on a big facet or a small one lol! Crown facet or through the table? and arms length being 20 inches thereabouts? there''s no sunlight in this room anymore, it''s all dim and diffused, I can go outside to do this or turn the overhead flourescent on... which would you prefer?

 

[Cehrabehra]

Date: 9/8/2006 8:17:12 PM
Author: Garry H (Cut Nut)

Date: 9/8/2006 8:10:18 PM
Author: Cehrabehra
Okay this is from that last pic, just a little piece of it toward the middle left... and it describes what I think garry was saying about white drowning out green?

Yes, exaclty C

this is the other thread that also is relevant to this one
https://www.pricescope.com/community/threads/new-eyeglasses-anti-reflective-coating-is-sapping-out-my-diamonds-fire.50457/
» New eyeglasses - anti-reflective coating is sapping out my diamond''s fire!

I suspected that was the thread, I read the first post and felt sorry for the poster and didn''t continue since I don''t have glasses! lol I''ll check it out now though, thanks for the link

 

[Cehrabehra]

Garry - just to get back on topic for a second while I have your attention on this... when you have a fancy yellow diamond (or blue or pink) and let''s say a large one, at least a carat to get some good feedback, how is colored light return affected? Does everything get tinted yellow or do you not even see yellow because it is drowned out? in my head I imagine blues and purples refract better from a blue stone, I have a hard time seeing orange come out of it... but does it?

 

[Garry H (Cut Nut)]

Date: 9/8/2006 8:18:15 PM
Author: Cehrabehra



so count the flashes at arms length on *one* of the facets? Do you want it on a big facet or a small one lol! Crown facet or through the table? and arms length being 20 inches thereabouts? there''s no sunlight in this room anymore, it''s all dim and diffused, I can go outside to do this or turn the overhead flourescent on... which would you prefer?

It is much better to use artificial light because that is what most of us see diamonds in most of the time. The sun has a very very small angle of beam because it is a very very long way away - it is like the light from a pin hole - and it does produce more green fire - we know that.

Dont just look at 1 facet - but if you want another experiment - one that shows what you showed in the photo with the burned out white centers - you can move the diamond so a big strong flash goes from blue to white and out the other side of the spectrum to yellow orrange red. The middle bit of the spectrum is almost always absent in very strong bright big flashes.

 

[Garry H (Cut Nut)]

Date: 9/8/2006 8:21:32 PM
Author: Cehrabehra
Garry - just to get back on topic for a second while I have your attention on this... when you have a fancy yellow diamond (or blue or pink) and let''s say a large one, at least a carat to get some good feedback, how is colored light return affected? Does everything get tinted yellow or do you not even see yellow because it is drowned out? in my head I imagine blues and purples refract better from a blue stone, I have a hard time seeing orange come out of it... but does it?

Yes - if there has been some absorption of blue light by the diamond - this makes it yellow - and as Marty and Dave said - you should expect to see a little less blue - but how much less - it should be very hard to pick I expect.

Maybe Sergey will join us - he''s the Man!!

 

[Cehrabehra]

Date: 9/8/2006 8:28:39 PM
Author: Garry H (Cut Nut)

Date: 9/8/2006 8:21:32 PM
Author: Cehrabehra
Garry - just to get back on topic for a second while I have your attention on this... when you have a fancy yellow diamond (or blue or pink) and let''s say a large one, at least a carat to get some good feedback, how is colored light return affected? Does everything get tinted yellow or do you not even see yellow because it is drowned out? in my head I imagine blues and purples refract better from a blue stone, I have a hard time seeing orange come out of it... but does it?

Yes - if there has been some absorption of blue light by the diamond - this makes it yellow - and as Marty and Dave said - you should expect to see a little less blue - but how much less - it should be very hard to pick I expect.

Maybe Sergey will join us - he''s the Man!!

thanks for indulging me, if you haven''t noticed i''m a bit of a spectral color freak! Not that I''m the most knowledgable on it, I just love to find it and see it and thankfully the stone I got has something to show in every light... I have yet to find a light I can''t find at least some refraction in.

 

[Cehrabehra]

this is my avatar and I did blow this up in size to look at it more closely... this is a flare from a single candle flame that I caught...

I thought it was interesting because you can see the white flare and then how the colors go off of it from there... and I wanted to mention, that part where it is red orange green - I see that a lot - it skips yellow! You can see the yellow here but it is displaced near the white... weird huh?

 

[Garry H (Cut Nut)]

Wow!

You say the camera is no good C? That is a great shot.

Here is one of Sergey''s for our upcoming article:
It was modelled with DiamCalc and based on actual light sizes and pupil diameters at set viewing distances etc

 

[Cehrabehra]

Date: 9/8/2006 8:52:52 PM
Author: Garry H (Cut Nut)
Wow!

You say the camera is no good C? That is a great shot.

Here is one of Sergey''s for our upcoming article:
It was modelled with DiamCalc and based on actual light sizes and pupil diameters at set viewing distances etc

that''s pretty!

the focus is really wonky on my camera - my nice camera was stolen last year on my BIRTHDAY and I bought this one and it sucks... it always focuses on the wrong thing grrrrrrrr I have very few clear shots of the facets on my stone... but this one you''re talking about was taken in the dark... no clue why the ones in the dark turn out so well... the ones by moonlight did too but I only took a handful because I was excited to come in and share LOL It''s a lot of fun to go out under the moon and see fire in your diamond like the sun was shining

hey Garry - did you see the question I had about identifying types of fire? I''d like your opinion on it... link here: https://www.pricescope.com/community/threads/help-me-identify.50527/ Mostly on type 3... but all of them if I am incorrect. Hey and in pic #1 I''m showing the pinfire and it isn''t a blurry mess!! hehehehe
thanks

 

[maxspinel]

Date: 9/8/2006 1:27:46 PM
Author: adamasgem

Date: 9/8/2006 2:39:20 AM
Author: maxspinel

I am trying to compare the image of the Y vs. E master stone side by side. The Y color master stone exhibits more and brighter yet narrower flashes/fire while the E color one has broader flashes. Based on the comparison, it seems cut instead of color is the main factor affecting the pattern and the amount of fire. Your observations are entirely correct, in my opinion. The smaller patterning (virtual facets) in not so well cut stones becomes evident in my Fire Performance Scope. The better the optical symmetry, the larger the areas of apparent facets of one color appear.

I am still confused about the difference between the brilliancescope and the fire scope. How different is the setup and if the brilliancescope is devised to measure brillance (white light return) and the fire acope is for the internal fire display (color light return).

I can''t speak directly to the brilliance scope methodologies, but it appears to offer a reasonably valid assessment vis-a-vie fire potential under a set of envirionments.

The photos in my Fire Performance Scope certainly tell a different type of story, and may be able to be used (at least the research I have done seems to indicate so), for a very good categorization of fire.
The photos, when compared with the old AGS cut grade, correlated extremely well from a visual perspective. The photos told you whether you had a well cut stone or not. Garbage was really evident.
When I get a chance I''ll dig up and post a photo of real bad cutting.

Thanks

I put all 3 images together for comparison. Judging from the pictures, the fire scope captures the light return especially the display of color very well. It is probably due to the darker background and the 10,000 even light sources that you mentioned. I once had to devise an experiment to capture a jet of water vapor exhausting from an air conditioning duct. I had to try various lighting and background to accomplish the optimum results.

I''ve learnt a lot from this thread. Based on some of the discussion, I''ve attempted to draw the following conclusions:

1) Fire scope and brilliance scope are both devised to measure the light return of a diamond. The light soucese, angle/distance of the light and background are different to achieve different visual objectives.

2) Diamond, just like any medium, posses certain characteristics to be able to absorb, reflect and refract the light. Cut is the most important factor that will affect how a diamond will refract and reflect the light, thus the resulting brilliance and fire.

3) Various light sources consists of different spectrum of lights which travels at different wave lengths. UV is rich in blue while incandelscent is rich in orange/red. Various light sources and viewing angles will affect the brlliance/fire display. As the light enters the diamond, some will be absorbed or leaked out, other will be reflected back or dispersed into different spectral colors.The dispersed colors, while being reflected back to the viewer, can also also combine with other reflected spectrals into white light. It is very hard to distinguish white and color light because they co-exist.

4) Body color reflects the outcome of the lights absorbed. A black diamond will not have any fire or brillance since all spectral colors are absorbed. A darker colored diamond will be less brillant as a lot of energy is absorbed and most of the spectrum color being absorbed will be missing from the viewer. However, the basic patterns of fire and brillance will not be altered by the body color, since it is primarily determined by the cut. For a very light yellow colored diamond (L-M), the effects on fire and brillance should be minimal.