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Eye color vs. grading color

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surfgirl

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I''ve been discussing on another thread about a ring/stone I''m considering for my ering and it brought up an issue that I thought might warrant a separate thread. The issue is the eye color of a stone in different settings vs. the grading color.

For example, I''m looking at an ungraded antique cut stone that''s being sold as an I/VVS-VS1 (I haven''t had it appraised yet). I have another stone - also antique cut - that was already appraised at G-H/SI1. When I put both rings on my fingers in the store (under what I think is halogen lights), they look very similar in color and they both blaze with fire and sparkle. When I take them outside and look at them in either shade, overcast daylight or in my shadow, they both sparkle like crazy and are extremely white and very clear to look into. But as soon as I put both stone in direct bright sunlight, they wash out to a grayish color. Actually, more in the middles and lighter towards the edges. My point is, in any light EXCEPT direct sunlight, the both look amazing. Is this fairly common of diamonds in direct sunlight and if so why? Is the amount of light forced into/out of the stone so much that it washes it out, so to speak? I''m just curious. The same thing happened to my friend''s stone and it is a modern rb cut. Thanks for any thought you all might have on this.
 

Regular Guy

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Surfgirl,

I read here this is not uncommon. There has been better discussion, but you may find this of some assistance.
 

surfgirl

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Thanks for that link Ira. I read it but it''s a brief thread and I didn''t really get WHY a diamond looks blackish/gray in the middle in direct sunlight. Maybe I''m a dunce?!
 

oldminer

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When people look at a set diamond they tend to block some of the light with their head''s shadow. This creates a darker set of zones in the diamond. When one color grades a diamond it is generally done through the side of the stone without any light blockage.

These different lighting strategies lead to different appearances to the eyes. It all makes sense and is a pretty simple situation unless one wants to create confusion by making it far more scientific.
 

Cehrabehra

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Garry talks a lot about how dark well cut diamonds look in the sun, and I admit that mine does take on a dark appearance but it has so much fire zinging off of it - who cares??? hehe
 

Cehrabehra

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Date: 4/10/2007 7:14:13 AM
Author: oldminer
When people look at a set diamond they tend to block some of the light with their head''s shadow. This creates a darker set of zones in the diamond. When one color grades a diamond it is generally done through the side of the stone without any light blockage.

These different lighting strategies lead to different appearances to the eyes. It all makes sense and is a pretty simple situation unless one wants to create confusion by making it far more scientific.
I don''t think she''s talking about obstruction, I know I wasn''t referring to obstruction.

To the OP: Garry has this thing he tells people to do - go outside and put the diamond against a white background - then put it against a black background. Some of what it is is optical illusion that the diamond will look darker against lighter backgrounds.

But I don''t know the rest of it... hopefully garry will pipe up and give the full scientific schpeel for the geeks :D
 

JohnQuixote

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Date: 4/10/2007 10:11:29 AM
Author: Cehrabehra

To the OP: Garry has this thing he tells people to do - go outside and put the diamond against a white background - then put it against a black background. Some of what it is is optical illusion that the diamond will look darker against lighter backgrounds.

But I don't know the rest of it... hopefully garry will pipe up and give the full scientific schpeel for the geeks :D
I can help here, Cehra. The natural the way our eyes react to greater ambient light makes diamonds appear darker outdoors when it's bright. Here's a photo Garry and Sergey have used to demonstrate this with colored CZs. The bottom photo was taken in brighter lighting than the top photo (compare the white backgrounds). The camera's auto exposure adapts to the background in the same way our eyes do. Garry has a number of photos like this using different backgrounds and illumination scenarios.

CCandLagain.jpg
 

surfgirl

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John, thank you! for that photo. That is exactly what I''m talking about. It''s not the blocking the light with one''s head that I meant, because in those cases the stones look better to my eye - whiter, cleaner and more fire and sparkle. It''s when you put a diamond in total direct sunlight and look into it and it goes "dead" in the center, with a darker, grayish look. You might get a "flash" from the direct sunlight, but it''s not a "fire flash", it''s just a big ol gash of blinding white, and not very beautiful. And yet when you take the same stone and move slightly into your own shadow it clears up inside and gives off wonderful flashes of color burst. So if I understand your explanation correctly, it''s not the stone, it''s the human eye''s ability to see within a specific spectrum? Is that it?

Cehra, you''re stone seems like an old cut, is it? And if so, can I ask where you got it from?
 

JohnQuixote

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Date: 4/10/2007 1:49:15 PM
Author: surfgirl

John, thank you! for that photo. That is exactly what I'm talking about. It's not the blocking the light with one's head that I meant, because in those cases the stones look better to my eye - whiter, cleaner and more fire and sparkle. It's when you put a diamond in total direct sunlight and look into it and it goes 'dead' in the center, with a darker, grayish look. You might get a 'flash' from the direct sunlight, but it's not a 'fire flash', it's just a big ol gash of blinding white, and not very beautiful. And yet when you take the same stone and move slightly into your own shadow it clears up inside and gives off wonderful flashes of color burst. So if I understand your explanation correctly, it's not the stone, it's the human eye's ability to see within a specific spectrum? Is that it?

Cehra, you're stone seems like an old cut, is it? And if so, can I ask where you got it from?
You're welcome - glad it helped. It has to do with the way our eyes adapt - both to the strength of the lighting in our environment and the background you see the diamond against.

Taking this to an extreme; have you ever walked from bright sunlight into a dark theater? You're blind until your eyes adjust. That adjustment is similar to the small adjustments they make just moving the diamond out of direct sunlight into a shaded area as you describe.
 

surfgirl

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Thanks John...So to sum it all up, a diamond that looks dark or gray in the center when its viewed in direct sunlight isn''t a "bad" diamond, it''s just the lighting and how our eyes are seeing it, right? I mean, if it has amazing scintillation and fire and looks clear to our eye in all other lighting then its not really an issue, right?
 

Cehrabehra

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Date: 4/10/2007 1:49:15 PM
Author: surfgirl
John, thank you! for that photo. That is exactly what I''m talking about. It''s not the blocking the light with one''s head that I meant, because in those cases the stones look better to my eye - whiter, cleaner and more fire and sparkle. It''s when you put a diamond in total direct sunlight and look into it and it goes ''dead'' in the center, with a darker, grayish look. You might get a ''flash'' from the direct sunlight, but it''s not a ''fire flash'', it''s just a big ol gash of blinding white, and not very beautiful. And yet when you take the same stone and move slightly into your own shadow it clears up inside and gives off wonderful flashes of color burst. So if I understand your explanation correctly, it''s not the stone, it''s the human eye''s ability to see within a specific spectrum? Is that it?

Cehra, you''re stone seems like an old cut, is it? And if so, can I ask where you got it from?
hehe this is a perfect place to pimp my stone as I have an on topic picture! ha!! ;-)

I TOTALLY beg to differ on the yellow part above, at least for my stone... it is a total fireball of colored light in direct sun... I can''t even tell you how easy it is for me to get colored shots of my stone because it''s very difficult to NOT get color, in fact in direct sun I have yet to not take a photo that has a colored flare and I myself do find them quite beautiful even if the backdrop is a dark looking stone itself - see pic below :)
cbOMC100.jpg


The photo in my avatar https://www.pricescope.com/community/threads/cbs-omc-pix.50194/page-6 is taken on a bright sunny day under a tree and I''m wearing a pink shirt I *think* though I don''t remember - but I must have been LOL You see greens and pinks and blues and skin colors... and the whole stone looks more alive with color - but I don''t know what everyone else''s stones are doing in direct light that they don''t love them, but I LOVE my stone in direct light... between the tiny colored pinfires and the medium fires and the huge fires off of the big (ugly bowtie) facets (previous said with total tongue in cheek lol) are just amazing to me - total retina burners!!!! I hate it when garry says diamonds look ugly in bright light but he''s obviously seeing something different than I!
cbOMC26.jpg


another shot under trees in diffused light:
cbOMC105.jpg


And the stone was cut in 2006 but it is an "Old Mine Brilliant" which is patterned after an old mine cut but with more consideration toward interaction between facets, better symmetry, polish etc. Still has a very high crown, an open culet, and I just love it. It is a different creature than an ideal round brilliant and frankly I want one of each!!! They are at extremes IMO :) Well, the non-dead extremes!! :D
 

Cehrabehra

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Date: 4/10/2007 3:39:26 PM
Author: surfgirl
Thanks John...So to sum it all up, a diamond that looks dark or gray in the center when its viewed in direct sunlight isn''t a ''bad'' diamond, it''s just the lighting and how our eyes are seeing it, right? I mean, if it has amazing scintillation and fire and looks clear to our eye in all other lighting then its not really an issue, right?
it has no fire and scint in bright light at all? Just like a dark blob? Well, you have a TRUE antique stone if I recall, and they had deep pavillions, generally speaking, and were designed to perform in low light situations. My stone has the high crown typical of old stones, but a rather shallow pavillion. If I follow Garry''s angle relationship thing on his hca my stone would still be in a red area just way further out of any sort of ideal range for a round. I think at least. My earring stones have very deep pavillions and they are enormously bright and white but I have trouble teasing even the slightest color out of them in the most ideal lighting situations... my ring stone is the opposite, I have to tease the white and fight the color LOL (though I don''t fight very hard ;-) )
 
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