Color change diamond

[RNgemlover]

This is a GIA certified 1.51 carat natural fancy gray diamond that is unlike anything I have ever seen. It changes to orangy yellow when the sky is overcast, or in fluorescent light. GIA did note the color change, but did not make a comment on the certificate. I actually talked to the gemologist who had the stone in his hand. Basically he said GIA didn't have a comment available for such a stone. That seems proposterous to me! Shouldn't they have researched this phenomenon a tiny bit better? The fluorescence is marked faint, so I don't think that is the cause. I have pictures, but they are too big for this site. Not sure I'm allowed, but I'll post them on my myspace page so you can take a look... Anyone ever seen anthing like this???

 

[platinumrock]

Hi Shaunrice, I''m not sure if mine qualifies as a color-change diamond, but it definitely changes hues in different lighting conditions. Mine is graded "Peachy Gray". For some reason, it looks pink when taken with the flash. Otherwise, it looks more lemony-peach in the daytime.

Your stone is stunning, by the way! The color change to green is awesome!

Here is a pic of mine taken under loupe under incandescent lighting:

 

[oneandahalfrock]

Maybe it''s just a bad picture but that one titled ''regular daylight'' makes the stone look cloudy to me... there are some other very promising pictures, but it doesn''t feel like there''s a lot of information to go off of.
There are a few untitled ones with a green tiny that look pretty cool, but I''m no pro

 

[Fly Girl]

Have you checked it yourself under UV light? The cert for my chameleon diamond said it had slight fluor, but it shows up as intense green under my UV. Only thing I can think of is that UV lights come in different wavelenths, and the stone is more reactive at some of them. BTW, my diamond is green under fluorescent lights and in natural sunlight (not direct), and yellow brown under incandescent lights. So, I think it is a color change diamond, too. Photos here. Link

 

[RNgemlover]

sunlight/incandescent light is the same for mine. change only occurs when a cloud goes over the sun, or i''m under fluorescent (not to be confused with uv) lights. So, the change occurs sans heat, sans darkness, but depends upon some kind of light. I''m sending it off... again IGI wants to evaluate it too...

 

[RNgemlover]

could really really use some feedback here guys, please help!

 

[RNgemlover]

No one knows? Or this is common and I''m a weirdo?

 

[oldmancoyote]

Not common at all - but I think without having serious gem-lab examination there isn't much anybody can say as to the whys and wherefores.

From the photos, I don't see so much colour change as the diamond picking up the colour of the lighting - which is exactly what I would expect a gray to do. Have you tried resetting white balance on a piece of white paper under the same lighting just before taking the pictures?

 

[RNgemlover]

I finally got some pictures of this phenomenon on overcast day. And it''s snowing. Again, orangy yellowish brownish color change. Can''t imagine what light source could do that. I also didn''t use a flash or anything. These last few were taken outside on a cloudy/overcast day.

 

[RNgemlover]

well, here it is in normal daylight, i sure hope this works! will add more if i can.

 

[RNgemlover]

Ok guys, this is under fluorescent kitchen light... Sorry about the size, my camera must be rather odd...

 

[Lorelei]

I wonder if it is phosphorescence you are seeing...

This is a section from GIA's paper on fluorescence.

Fluorescence is a form of luminescence. For the purposes
of this paper, luminescence is defined as the emission
of light by a substance that has absorbed UV radiation.
A substance is fluorescent if the emission of light
stops when the energy source causing it is removed. (In
contrast, if a substance continues to glow after the
energy source is removed, it is phosphorescent.)
In a luminescent substance, the absorption of UV
radiation causes an electron to move from its stable
low-energy position (“ground state”) into a temporary
high-energy (“excited”) state (figure A-1). This highenergy
state is unstable, so the electron relaxes into a
lower-energy excited state that is slightly more stable.
As the electron falls back to the ground state, the substance
emits light. This emitted energy is always less
than excitation energy. Since wavelength increases as
energy decreases, emission occurs at longer wavelengths
than the excitation wavelength (again, see figure
A-1). Submicroscopic structures that allow this
movement of electrons are called luminescence centers.
These centers arise from certain defects in the
crystal lattice, such as electrically charged ions, or
atomic vacancies or substitutions (see Nassau, 1983;
Waychunas, 198.

 

[RNgemlover]

And here it is while the sky is overcast.

 

[RNgemlover]

I am far from educated in regards to such things... Does that also help to describe this change of color due to a cloud crossing the sky too? And if in fact that is the reaction occuring, is it common? No on I have talked to has seen this reaction happen in a diamond before.

 

[RNgemlover]

with my boss''s diamond, normal lighting conditions.

 

[RNgemlover]

Here they are in the kitchen light. Sorry about these pictures, but they are soooo big

 

[RNgemlover]

Is this post in the right forum? No one really seems to be answering...

 

[oldmancoyote]

Shaun, to the cost of appearing rude - I think one of the reasons people may not be answering is because the effect you claim is not all that apparent in the photos. What I see - consistently - is the stone picking up the colour of the lighting and the camera''s white balance being incorrectly set. Both diamonds seem yellowish-greenish-grey in the photo under artificial light.

(To resize photos, using Microsoft Photo Editor (supplied with Windows) - use the Resize command under the Image menu, then set size to about 500 x 500 or so)

 

[RNgemlover]

Please close this thread