My positive experience with yellow fluorescence!

[l_ode]

I just wanted to share my experience with yellow fluorescence!
Seems like all you read about the topic (which is not very much at all) are negative aspects and people tend to be quite scared of yellow fluorescence.
With that said, not everyone might like it, but I still feel that it has a far worse reputations than I think it actually deserves.

There are quite few of them compared to diamonds with blue fluorescence. And seems like people are automatically rejecting the yellow fluorecent ones once they pop up. So maybe that's why it's quite hard to find any information regarding colorless/near colorless diamonds with this attribute. Therefor I really wanted to share my experience and maybe reduce some of that reluctance most people seem to have.

I was very hesitant too at first, mainly because I had no experience of my own in regards of yellow and had only read really negative things about it. Pretty much that you should stay away and that it would make the diamond look more yellow and look like a lower grade on the color scale. Also that it could appear milky (at least if the fluorescence was strong och very strong).
Still, I was curiouse and just bought and received a real beauty which had a medium yellow fluorescence.
I did not get to see the diamond before the purchase since I bought it online och therefor picked it from an online database. But I liked all the other aspects of the diamond based on the GIA certificate and the company assured me they would switch it for me in case I realized I did not like it.
(Short summary: it is a 0.6 carat, 3x, color H, VS2)

So..! In indoors in normal lighting you can't even tell, which seems to be the same for all fluorescent diamonds. It sparkles like crazy, especially under led lights. But no shade of yellow, it looks like the other diamonds.

And in direct sunlight, I can't pick up any yellow there either. I've been staring so much my eyes hurt but no tint, no nothing. It goes quite dark though which I've understood many well cut diamonds do.

And when it come to UV-light and fluorescence... When directing an UV-light at my wedding band, which contains 18 small diamonds, 13 of them instantly lights up in different beautiful blue colors.
But directing the UV-light at my yellow fluorescent diamond barely does anything! It pretty much just remains the same.
In order to pull some yellow out of it I have to go to a completely dark room, close the door and then point the uv-light directly at it. Then I can see a quite lovely yellow nuance. This requires that I hold the uv-light veeery close though.
However i think it is quite pretty and not something bad at all! Although, I kind of love fluorescence in all colors so I might be a bit biased

But I was a bit surprised that is was so hard to actually see the yellow fluorescence! I hade to work really hard and get the precise circumstances. With blue fluorescent diamonds, you can just point an uv-lamp at in anywhere and it will pop!

Conclusion for me is that my fear of yellow fluorescence was unfounded and unfair. I can basically not detect in at all unless I'm in a completely dark room pointing an uv-light directly at in. And even then, the yellow is quite faint. I thought it would be more distinct and would actually have wanted it to glow even more yellow, haha. If the UV-light is not very close the fluorescence almoste looks... white? As if the stone is just glowing with unspecified color.
Well, to me it looks lovely in all light settings but can actually only be detected in the scenario I just described.

Hope someone might find this a bit interesting and that it might lead to someone else not automatically not discarding a beauty based on fear.
I just love my diamond and really thinks the yellow flourescence just adds some personality and charisma to it!

I added a bunch of pictures as well!

Indoors, solitaire is the one with yellow fl


The wedding band which has maaany blue fl diamonds


Both of them in indirect sunlight


Yellow fl diamond in direct sunlight. It goes quite dark as mentioned.


Same diamond in direct sunlight, more from a distance


Three pics of yellow fl in totally dark room. Very hard to get sharp pics...

 

[Karl_K]

Example of one it was not an issue, I can counter with an example of one that with the slightest uv went yellow in spite of the gia med rating.
I would have called it very strong but the official grade was med.
Lesson, diamonds vary, uv grading leaves a lot to be desired.
Paying for no yellow tint then have it go yellow in some lighting leads to unhappy clients.

 

[l_ode]

Example of one ts was not an issue, I can counter with an example of one that with the slightest uv went yellow in spite of the gia med rating.
I would have called it very strong but the official grade was med.
Lesson, diamonds vary, uv grading leaves a lot to be desired.
Paying for no yellow tint then have it go yellow in some lighting leads to unhappy clients.

You're right in regards of what you're saying, but I think that is also sort of my point... There will always be exceptions going both ways. I was just hoping people should not just automatically (especially unseen) disregard all diamonds with yellow fluorescence just because of the written existence of it. Not saying everyone should go for them unseen either, like you say: there are yellow fluorescent stones that will be negatively impacted as well. Just want to balance out the picture a bit since all I could find when I was about to make my purchase was that they would all be really bad which I don't think is the case

 

[Karl_K]

I get what your saying but the color grade is based on the lack of yellow. Given that:
Paying for no yellow tint then have it go yellow in some lighting leads to unhappy clients.
Even the thought that it may turn yellow makes it not mind clean for many.

Myself something like a k or lower with a very reactive strong yellow would be a kewl toy I would enjoy but im not paying D-J color grade prices for a stone that might go yellow.

 

[oncrutchesrightnow]

Thanks, that was informative.

 

[Texas Leaguer]

@l_ode ,
Interesting post and good set of photos. Yellow fluorescence is quite rare compared to blue, which is why you do not hear much about it. At least not in diamonds in the normal D-Z range. Fancy color diamonds tend to have higher frequencies of non-blue fluorescence.

What you have observed about the fluorescence in your diamond is the same reason that fluorescence is considered primarily an identification characteristic and not a performance characteristic.

In most cases, even with strong fluorescence, the property will not have any discernible visual impacts (good or bad) in the majority of real life lighting environments.

 

[Garry H (Cut Nut)]

This is an interesting topic.
Firstly, the stronger yellow fluorescence is cause I believe by visible warmer light than by UV light. That causes the absorption of energy that creates the stronger effect.
Since GIA are grading in a broad spectrum light, it is possible that they may under grade diamonds with yellow fluorescence. I am not sure. Just hypothesizing.
I think your H may be an F in many lights.
Karl, Bryan, what do you think?


The above is from https://www.gia.edu/gems-gemology/summer-2013-luo-fluorescence-optical-defects

 

[Karl_K]

This is an interesting topic.
Firstly, the stronger yellow fluorescence is cause I believe by visible warmer light than by UV light. That causes the absorption of energy that creates the stronger effect.
Since GIA are grading in a broad spectrum light, it is possible that they may under grade diamonds with yellow fluorescence. I am not sure. Just hypothesizing.
I think your H may be an F in many lights.
Karl, Bryan, what do you think?

unlikely but not totally impossible.
Since I have seen a diamond that reacts to only some uv wavelengths and not others in almost a bandpass manner, I will say that nothing is impossible but if it exists is it common or a one of?

One of the advantages touted for mined diamonds is a store of value and yellow florescence on the report kills salability and reduces any stored value to a large degree. I dont see that changing anytime soon.

 

[Garry H (Cut Nut)]

One of the advantages touted for mined diamonds is a store of value and yellow florescence on the report kills salability and reduces any stored value to a large degree. I dont see that changing anytime soon.

On an aside,
Until a lot of investor money was ploughed into promoting LGD's, diamonds were diamonds, and they were called natural diamonds.
Somehow that lobby group managed to make diamonds un natural and mined or environmental disasters called earth mined diamonds!
Karl would you like to estimate when you began using the term 'mined' and was it conscious?

 

[Karl_K]

On an aside,
Until a lot of investor money was ploughed into promoting LGD's, diamonds were diamonds, and they were called natural diamonds.
Somehow that lobby group managed to make diamonds un natural and mined or environmental disasters called earth mined diamonds!
Karl would you like to estimate when you began using the term 'mined' and was it conscious?

When the mmd forum was added to PS, before that I had little need for a modifier.
If I had just said diamond that would have covered both mmd and mined and that was not what I meant.
I find man made diamond and mined diamond to be the most honest descriptions.

 

[Garry H (Cut Nut)]

When the mmd forum was added to PS, before that I had little need for a modifier.
If I had just said diamond that would have covered both mmd and mined and that was not what I meant.
I find man made diamond and mined diamond to be the most honest descriptions.

So natural is un natural?

 

[l_ode]

Thank you for the Link Garry! Just finished reading. So I’m getting this somewhat correctly I might have to try an UV lamp with a different wavelength, seems LWUV is preferred? Maybe different temperature and different nm? Not sure what the specs are on my UV lamp. But it is the very same handheld one which is mentioned in the study as well.

“In most diamonds, multiple defect centers occur together. Even under pure 365 nm LWUV excitation, the fluorescence color will be a mixture of the fluorescence from different defect centers.”
Could this be the reason I think that my diamond under most circumstances fluoresce white rather than yellow? Attached picture of how it looks most of the times under my UV lamp.

“Traditional gemological UV lamps and light sources used in the diamond industry produce widely variable emissions, making it difficult to achieve reproducible fluorescence observations.”
So I’m guessing I might not be able to reproduce the very same condition to reflect the grading medium yellow under normal living conditions?

 

[Garry H (Cut Nut)]

Thank you for the Link Garry! Just finished reading. So I’m getting this somewhat correctly I might have to try an UV lamp with a different wavelength, seems LWUV is preferred? Maybe different temperature and different nm? Not sure what the specs are on my UV lamp. But it is the very same handheld one which is mentioned in the study as well.

“In most diamonds, multiple defect centers occur together. Even under pure 365 nm LWUV excitation, the fluorescence color will be a mixture of the fluorescence from different defect centers.”
Could this be the reason I think that my diamond under most circumstances fluoresce white rather than yellow? Attached picture of how it looks most of the times under my UV lamp.

“Traditional gemological UV lamps and light sources used in the diamond industry produce widely variable emissions, making it difficult to achieve reproducible fluorescence observations.”
So I’m guessing I might not be able to reproduce the very same condition to reflect the grading medium yellow under normal living conditions?

White not yellow may be because your UV is probably around 395-405nm just visible violet /UV, not the 365 invisible that GIA say they use.
but as you say - the authors note - its not just one thing going on.
The complex charts I posted show that green light seems to create Red 635nm and green 539nm fluorescence which when combined make us see yellow.

Now I am in a bit over my depth here, but that is what I think happens with yellow fluorescence caused not by 365nm UV but by the very bright visible light used in the color grading process. You would not be able to "see" this fluorescence - but my theory is that this would lower the color of your diamond in strong white lighting.
So maybe your H in more normal light (not as bright as GIA's grading environment) is actually an F?

 

[l_ode]

White not yellow may be because your UV is probably around 395-405nm just visible violet /UV, not the 365 invisible that GIA say they use.
but as you say - the authors note - its not just one thing going on.
The complex charts I posted show that green light seems to create Red 635nm and green 539nm fluorescence which when combined make us see yellow.

Now I am in a bit over my depth here, but that is what I think happens with yellow fluorescence caused not by 365nm UV but by the very bright visible light used in the color grading process. You would not be able to "see" this fluorescence - but my theory is that this would lower the color of your diamond in strong white lighting.
So maybe your H in more normal light (not as bright as GIA's grading environment) is actually an F?

Ok, makes sense! Although I CAN get a visual of the yellow (quite faint though) if I go to a dark room and hold the very same UV light veeery close to the diamond. So I guess condition in combination with nm? I think this is so interesting!

Oh, I see your point! In that case I would regard that as a positive thing however I’m not sure I’m skilled enough to actually see the difference between H and F by just looking at a single diamond.

 

[l_ode]

Just realized that I might have assumed that “medium yellow” would be a grading of how much yellow would be visible when under UV light whereas it might actually point to the degree of actual fluorescence itself (color just being a note)? Meaning that the level of fluorescence IS medium regardless that the actual yellow color seen is very faint? Does this make sense? Because as mentioned, it DOES fluoresce quite a bit under some circumstances but most often not yellow or just faint yellow.

 

[l_ode]

Another thought, Garry (sorry for the spam! )

Just read another article maybe confirming what you said:

“Colorless diamonds with yellow or orange fluorescence will appear to be a lower color when seen in light with a strong UV component”

Which then might confirm your thoughts on GIA grading these diamonds lower. Which then means (?) that an H diamond is H at its worst but would be higher in other lighting conditions as you mentioned?

Could it then be a misconception that people in general, not knowing in which light conditions GIA does the grading, assumes that an H diamond would be a J diamond under some circumstances instead of being aware of the fact that the diamond has already been downgraded when it receives the H?

 

[Texas Leaguer]

This is an interesting topic.
Firstly, the stronger yellow fluorescence is cause I believe by visible warmer light than by UV light. That causes the absorption of energy that creates the stronger effect.
Since GIA are grading in a broad spectrum light, it is possible that they may under grade diamonds with yellow fluorescence. I am not sure. Just hypothesizing.
I think your H may be an F in many lights.
Karl, Bryan, what do you think?


The above is from https://www.gia.edu/gems-gemology/summer-2013-luo-fluorescence-optical-defects

Garry,
Yes, it is theoretically possible. Since blue-fluorescence tends to cancel some yellow body color it thereby whitens the appearance. Yellow fluorescence presumably has the opposite effect, adding to the body color.

So, to the extent that blue fluorescent diamonds might be overgraded, then it's logical to also consider the possibility that yellow fluorescent diamonds might be undergraded.

However, this is not much of a factor in diamonds of fluorescence intensity of medium or below. I would definitely NOT expect an H color to look like an F !!!

 

[Garry H (Cut Nut)]

Garry,
Yes, it is theoretically possible. Since blue-fluorescence tends to cancel some yellow body color it thereby whitens the appearance. Yellow fluorescence presumably has the opposite effect, adding to the body color.

So, to the extent that blue fluorescent diamonds might be overgraded, then it's logical to also consider the possibility that yellow fluorescent diamonds might be undergraded.

However, this is not much of a factor in diamonds of fluorescence intensity of medium or below. I would definitely NOT expect an H color to look like an F !!!

I agree Bryan, but just putting it out there as a theory, not a fact It is an interesting issue that I never actually considered in any depth.
I am co writing a series of 3 fluoro papers with Grant Pearson who is way above my pay grade. I will get his opinion as we do some editing.