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FADING of fancy yellow diamond

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Hello all,

This is my first significant yellow diamond purchase (2.27ct.), and I'm experiencing something very unexpected. I am hoping someone here with extensive fancy diamond experience can provide me with some insight. I have researched for days to find an answer to this online, but have come up with zip on the subject. The diamond has a GIA report, but it hasn't proven to be very helpful. I was delighted when I first received this diamond. The color looks more like a fancy intense than a fancy yellow. It's eye clean, the color is even, and the cut is extremely brilliant. It's a bit of an unusual "cushion" shape (slightly rounded), but since it doesn't affect the brilliance, it doesn't bother me.

The issue arises when I put it under my UV lamp. It has very strong fluorescence, which, again, didn't bother me because it exhibits zero cloudiness even in direct sunlight. However, the stone's vibrant fancy yellow color fades to a dull brown after UV exposure, and takes several minutes to return to its original color. The vendor, who is regarded as being very reputable, tells me that this is a common optical property amongst yellow diamonds... the nitrogen impurities cause the stones to brown out under UV, with the stones eventually regaining their original color after a few minutes. But this is all news to me, and I'm wondering if there's any truth to it or if I purchased an inferior diamond. I should mention the stone also phosphoresces brightly for several minutes after removing it from under the lamp. I'm assuming these two phenomena are related.

I look forward to any information on the subject any members could provide. Thank you in advance!

Alison
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Is it a chameleon? Does the GIA say chameleon in the note? Maybe not since chameleon color change is activated by heat...

Hmmm this is very interesting... thank you for mentioning it. I did read about chameleons, but it doesn't quite seem to fit my experience with this stone. Chameleons tend to deepen or intensify in color when exposed to heat (or light, after prolonged darkness). My stone actually fades (significantly) when exposed to UV. I'd really like to know if this is common amongst yellow diamonds or if this is a sign of a flawed stone. I'm stumped!

ETA: To answer your question, the GIA only lists the diamond as "fancy yellow" with a natural color origin and an "even" distribution of color. :wall:
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Patient: "Doc it hurts when I do this"

Doc: "Don't do that!"

This is what comes to mind. It is fascinating and I'm eager to hear what the diamond experts think.

lol My OCD isn't cooperating, unfortunately. What I'm afraid of is eventually setting the stone, wearing it out in the sunlight for the day, and coming home with a brown diamond. I plan on testing it out by leaving it in the sun for a few hours, and seeing if the results are the same as under my UV lamp. This is a large purchase for me that I don't want to regret down the line. I, too, am interested to see if any experts here have had experience with this issue!
 

Niel

Super_Ideal_Rock
Premium
Joined
Jul 23, 2012
Messages
19,286
It sounds like it has phosphorescence maybe? I’m no expert but that to me would account for a different color after being exposed to uv light for a bit.
have you tried flashing it with uv light in the dark? Does it glow in the dark afterwards? Once you turn the light off?
ETA: that’s what I get for not reading your whole post. I see it is phosphorescent.
sounds like that’s the reason to me. I’m sure actual experts can chime in.
 
Last edited:

Rfisher

Ideal_Rock
Premium
Joined
Oct 19, 2013
Messages
3,435
Was it priced lower than a comparable fancy yellow with no fluorescence?
The brown tint (according to Lebish) isn’t uncommon but they don’t mention the brown hanging around for a time after, either.
Can you capture some pictures and share? This is interesting.
Does GIA report state what color fluorescence? And also states color as yellow, no modifiers?

I only have a small yellow with some fluorescence, so I don’t have extensive experience. I do know it looks more and less yellow in certain lighting. I don’t see it as brown though, nor does it hang around.
I guess return it if it doesn’t thrill you? One out there will. :)
 
Last edited:

Tourmaline

Brilliant_Rock
Premium
Joined
Nov 17, 2013
Messages
1,942
This is fascinating! If it's only for a few minutes after exposure, don't worry about it! I would have so much fun playing with those attributes! Some of the stones in my AVC band (they are light yellow) have strong blue fluorescence and strong orange phosphorescence that lasts for hours. I find that to be so much fun!
 

Gemly

Shiny_Rock
Joined
May 29, 2020
Messages
293
We’d love to see pictures if you have a chance. I would assume the few minute time period of the color change will apply weather it’s under UV for a few minutes or a few hours. To me, this is super cool and exciting! But....would love to see the before and after color change to see if it’s a visually aesthetic shift.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,542
Yellow diamonds with strong fluorescence trade at steep discounts because of the negative effects on the color, when exposed to UV lighting. This can occur even when exposed to indirect sunlight in some stones.
No, there’s no lasting effect although your eyes might need a while to adjust afterwards depending on your eyes and environmental factors.
 

Avatar345

Shiny_Rock
Joined
Mar 23, 2021
Messages
126
This is fascinating! If it's only for a few minutes after exposure, don't worry about it! I would have so much fun playing with those attributes! Some of the stones in my AVC band (they are light yellow) have strong blue fluorescence and strong orange phosphorescence that lasts for hours. I find that to be so much fun!

Wait, are those orange phosphorescent diamonds natural?
Man I thought that was a pretty rare property in a natural - sort of cool!
 

Avatar345

Shiny_Rock
Joined
Mar 23, 2021
Messages
126
Hello all,

This is my first significant yellow diamond purchase (2.27ct.), and I'm experiencing something very unexpected. I am hoping someone here with extensive fancy diamond experience can provide me with some insight. I have researched for days to find an answer to this online, but have come up with zip on the subject. The diamond has a GIA report, but it hasn't proven to be very helpful. I was delighted when I first received this diamond. The color looks more like a fancy intense than a fancy yellow. It's eye clean, the color is even, and the cut is extremely brilliant. It's a bit of an unusual "cushion" shape (slightly rounded), but since it doesn't affect the brilliance, it doesn't bother me.

The issue arises when I put it under my UV lamp. It has very strong fluorescence, which, again, didn't bother me because it exhibits zero cloudiness even in direct sunlight. However, the stone's vibrant fancy yellow color fades to a dull brown after UV exposure, and takes several minutes to return to its original color. The vendor, who is regarded as being very reputable, tells me that this is a common optical property amongst yellow diamonds... the nitrogen impurities cause the stones to brown out under UV, with the stones eventually regaining their original color after a few minutes. But this is all news to me, and I'm wondering if there's any truth to it or if I purchased an inferior diamond. I should mention the stone also phosphoresces brightly for several minutes after removing it from under the lamp. I'm assuming these two phenomena are related.

I look forward to any information on the subject any members could provide. Thank you in advance!

Alison

What color does it phosphoresce in the dark?
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Was it priced lower than a comparable fancy yellow with no fluorescence?
The brown tint (according to Lebish) isn’t uncommon but they don’t mention the brown hanging around for a time after, either.
Can you capture some pictures and share? This is interesting.
Does GIA report state what color fluorescence? And also states color as yellow, no modifiers?

I only have a small yellow with some fluorescence, so I don’t have extensive experience. I do know it looks more and less yellow in certain lighting. I don’t see it as brown though, nor does it hang around.
I guess return it if it doesn’t thrill you? One out there will. :)

Thank you for the comment! The GIA report does not state fluorescence. And, yes, it lists the color only as "fancy yellow." It doesn't have a brown modifier until it begins to phosphoresce. I will try to snap some photos for sure!
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Yellow diamonds with strong fluorescence trade at steep discounts because of the negative effects on the color, when exposed to UV lighting. This can occur even when exposed to indirect sunlight in some stones.
No, there’s no lasting effect although your eyes might need a while to adjust afterwards depending on your eyes and environmental factors.

Thank you for your input! Oddly, the strong fluorescence does not affect the stone's performance even in direct sunlight... no milkiness or change in color. The trouble begins after exposure to my UV lamp. There is a definite loss of color after removal for several minutes. After checking with a couple of GIA grads, I am starting to agree with others on this thread that the phosphorescence is the culprit. So now the question is whether I can live with this phenomenon or not. It is fascinating to witness, but a bit troubling as well! Once we have some sunlight here again, I am going to leave the stone in the sun for a few hours, to see if the effect is the same as exposure to the UV lamp. I think that will be the deciding factor for me.
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
It sounds like it has phosphorescence maybe? I’m no expert but that to me would account for a different color after being exposed to uv light for a bit.
have you tried flashing it with uv light in the dark? Does it glow in the dark afterwards? Once you turn the light off?
ETA: that’s what I get for not reading your whole post. I see it is phosphorescent.
sounds like that’s the reason to me. I’m sure actual experts can chime in.

No worries, lol, it was a long post. Thank you for taking the time to reply... I agree with you!
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
This is fascinating! If it's only for a few minutes after exposure, don't worry about it! I would have so much fun playing with those attributes! Some of the stones in my AVC band (they are light yellow) have strong blue fluorescence and strong orange phosphorescence that lasts for hours. I find that to be so much fun!

I appreciate the pep talk, thank you! The ring in your profile pic is stunning. Is that an antique cut? :love:
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
We’d love to see pictures if you have a chance. I would assume the few minute time period of the color change will apply weather it’s under UV for a few minutes or a few hours. To me, this is super cool and exciting! But....would love to see the before and after color change to see if it’s a visually aesthetic shift.

I am going to try to capture it, Gemly! Thank you!!
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
It sounds concerning to you, and (even if a sound/scientific explanation exists) it is something you don't like about the stone -- if you are within your return period, I suggest that you return it for full refund and start the search again.

This was my first instinct... whenever I stick something out, but have initial reservations, I tend to regret it later on. The tricky part is how good this stone looks otherwise. Thank you for your opinion!
 

Avatar345

Shiny_Rock
Joined
Mar 23, 2021
Messages
126
Neon yellow! The fluorescence, however, is white.

Oh wow that is crazy!!
And it wasn't marked as fluorescent at all on the GIA?

I have to say given the bright white and all, it's hard to fathom where the brown comes from, but... interesting diamond!
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Oh wow that is crazy!!
And it wasn't marked as fluorescent at all on the GIA?

I have to say given the bright white and all, it's hard to fathom where the brown comes from, but... interesting diamond!

You would think it would enhance the yellow! Nope, it fades right out.

ETA: The GIA report doesn't grade fluorescence at all for some reason.
 

Attachments

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,542
It’s a “Color Origin” GIA report. This type of report omits clarity and fluorescence, table and depth percentages.
 

Avatar345

Shiny_Rock
Joined
Mar 23, 2021
Messages
126
You would think it would enhance the yellow! Nope, it fades right out.

ETA: The GIA report doesn't grade fluorescence at all for some reason.

Definitely take it out into the sun and bring it back in; shouldn't need a few hours... shouldn't need 30 minutes

If the phosphorescence doesn't trigger from the sunlight, and it's only the fluorescence, then maybe it's a particular UV wavelength your UV light is putting out and it won't ever really come into play in the 'normal' world. If the sunlight *does* trigger the phosphorescence, then well... it's probably going to have that same browning effect because why wouldn't it?

It still might be worth it all just to have such a large ct weight diamond with such unique properties lol
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
Definitely take it out into the sun and bring it back in; shouldn't need a few hours... shouldn't need 30 minutes

If the phosphorescence doesn't trigger from the sunlight, and it's only the fluorescence, then maybe it's a particular UV wavelength your UV light is putting out and it won't ever really come into play in the 'normal' world. If the sunlight *does* trigger the phosphorescence, then well... it's probably going to have that same browning effect because why wouldn't it?

It still might be worth it all just to have such a large ct weight diamond with such unique properties lol

Exactly... I agree 100%. That is going to be the deciding factor for me. I'll try to snap some photos too. Can we post videos here?
 

AutumnInNewEngland

Rough_Rock
Joined
Jan 20, 2012
Messages
70
It’s a “Color Origin” GIA report. This type of report omits clarity and fluorescence, table and depth percentages.

I think it may be worth it to have the stone graded again with a full diamond report, just to see if anything's changed according to the GIA's newer instruments/guidelines/etc. I have a 60-day return period.
 
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