Phosphorescence

[Roselina]

I stumbled over this topic because Nikki1415 mentioned it in relation to her gorgeous OEC target ring. I have heard of fluorescence but not phosphorescence before. Doing a bit of research I came across this article about the (blue) Hope diamond: https://www.sciencedaily.com/releases/2008/01/080104145404.htm. It states: "Other colors of diamonds do not phosphoresce, but fluoresce, emitting visible light only as long as they are stimulated with ultraviolet radiation. Blue diamonds that phosphoresce emit light even after the ultraviolet lamp is turned off. Unlike the Hope, however, most blue diamonds produce a bluish light rather than reddish light."
However, I came across some examples in this forum of (non blue) diamonds that have the effect of phosphorescence as well. And checking my strong blue fluorescence diamond it turns out it has it too (other with fluorescence don't). I'm rather confused now...

And this: https://www.capetowndiamondmuseum.o...cent-diamonds-help-identify-fakes-and-frauds/
It is talking of type IIb diamonds (blue) having phosphorescent. But then - as I now see - some diamonds with a strong fluorescence have phosphorescence as well and glow on in the dark. Is this just another form of phosphorescence compared to the one in type IIb diamonds?

 

[foxinsox]

No idea but following as I have a couple of small diamonds that phosphoresce orange.. so I’m keen to know what’s behind that

 

[Matthews1127]

I stumbled over this topic because Nikki1415 mentioned it in relation to her gorgeous OEC target ring. I have heard of fluorescence but not phosphorescence before. Doing a bit of research I came across this article about the (blue) Hope diamond: https://www.sciencedaily.com/releases/2008/01/080104145404.htm. It states: "Other colors of diamonds do not phosphoresce, but fluoresce, emitting visible light only as long as they are stimulated with ultraviolet radiation. Blue diamonds that phosphoresce emit light even after the ultraviolet lamp is turned off. Unlike the Hope, however, most blue diamonds produce a bluish light rather than reddish light."
However, I came across some examples in this forum of (non blue) diamonds that have the effect of phosphorescence as well. And checking my strong blue fluorescence diamond it turns out it has it too (other with fluorescence don't). I'm rather confused now...

And this: https://www.capetowndiamondmuseum.o...cent-diamonds-help-identify-fakes-and-frauds/
It is talking of type IIb diamonds (blue) having phosphorescent. But then - as I now see - some diamonds with a strong fluorescence have phosphorescence as well and glow on in the dark. Is this just another form of phosphorescence compared to the one in type IIb diamonds?

Also following.
My sister in law has blue diamonds, in very rare deep blue.
Curious to know how this May impact her diamonds.

 

[elizat]

No idea but following as I have a couple of small diamonds that phosphoresce orange.. so I’m keen to know what’s behind that

My pear in my avatar does as well. Impossible to catch in a photo, but it does.

 

[stepcutnut]

My Chameleon pear has orange phosphorescence and one of my OMC has yellow, I find it pretty fascinating

 

[Roselina]

I captured it - looks stronger in real...

 

[whitewave]

At the geology museum we visited at the Boise get together last year

 

[Roselina]

 

[Demon]

I have 3 diamonds that show phosphorescence:

I have a J with strong blue fluorescence that shows phosphorescence briefly

A chameleon that shows it longer

and a green-yellow with strong blue fluorescence that shows phosphorescence for a good bit.

 

[MonkeysInk]

A little off topic: the article that is linked in the OP was from the study done by the GIA scientist Dr. Sally Eaton-Magana that talked to our PS group last year. Wishing we were all there looking at diamonds again right now! Her talk on fluorescence and phosphorescence was really interesting and she was so funny and casual about getting to handle the Hope Diamond.


I hope our @psadmin team is dreaming up some new adventure for when we can all travel again.

 

[Roselina]

So the conclusion be, that type IIb blue diamonds have phosphorescence but also type Ia with strong to very strong fluorescence can (but not in any case) have phosphorescence. Is that about right? I wonder how many stones with strong fluorescent also have phosphorescence - the phenomenon does seem less rare than first thought.

 

[acebruin]

I'm not sure what type it is. But my Fancy Intense Yellow EC has a strong blue fluorescence and yellow phosphorescence.

 

[Demon]

So the conclusion be, that type IIb blue diamonds have phosphorescence but also type Ia with strong to very strong fluorescence can (but not in any case) have phosphorescence. Is that about right? I wonder how many stones with strong fluorescent also have phosphorescence - the phenomenon does seem less rare than first thought.

I think it was said on here before that strong blue fluorescence is what can lead to phosphorescence. I also have an intense green-yellow with strong green fluorescence, but no phosphorescence.

 

[WinkHPD]

I stumbled over this topic because Nikki1415 mentioned it in relation to her gorgeous OEC target ring. I have heard of fluorescence but not phosphorescence before. Doing a bit of research I came across this article about the (blue) Hope diamond: https://www.sciencedaily.com/releases/2008/01/080104145404.htm. It states: "Other colors of diamonds do not phosphoresce, but fluoresce, emitting visible light only as long as they are stimulated with ultraviolet radiation. Blue diamonds that phosphoresce emit light even after the ultraviolet lamp is turned off. Unlike the Hope, however, most blue diamonds produce a bluish light rather than reddish light."
However, I came across some examples in this forum of (non blue) diamonds that have the effect of phosphorescence as well. And checking my strong blue fluorescence diamond it turns out it has it too (other with fluorescence don't). I'm rather confused now...

And this: https://www.capetowndiamondmuseum.o...cent-diamonds-help-identify-fakes-and-frauds/
It is talking of type IIb diamonds (blue) having phosphorescent. But then - as I now see - some diamonds with a strong fluorescence have phosphorescence as well and glow on in the dark. Is this just another form of phosphorescence compared to the one in type IIb diamonds?

@Roselina, thank you for the memories you bring up with phosphorescence. A friend of mine in the trade asked me to bring a beautiful blue sapphire of about 15 carats, if memory serves, to show to Zell Brothers in Portland, who had expressed interest in seeing it after he had described it to them. Nothing came of showing them the sapphire but we then drove to Eugene and met with another friend of ours and we talked for hours and played with gems.

He asked me if I had ever seen any phosphorescent diamonds. I had not. He then pulled out a parcel of six or seven diamonds of various shapes and sizes. After turning out the lights, he exposed them to fluorescent lighting. When he turned the fluorescent lighting off the stones glowed on, slowly fading away until only the star of his show was still on. I remember it glowing, ever more feebly, for nearly 5 minutes.

I was glad that you mentioned seeing non blue diamonds displaying phosphorescence, as I know from personal experience that this was an incorrect statement. It is not a very common phenomenon, so it is easy to see how the writers of the article might have thought that.

I remember when I was at GIA in 1975 that our gem identification instructor was laughing that GIA had been teaching that a gem had to be doubly refractive to display color change such as is common in alexandrite. It simply was not possible in a singly refractive stone. A few days earlier, someone had brought into the lab a color change garnet, which is singly refractive and thus could not display a color change. He knew they were going to have to figure out why it could happen, and they did, eventually, but it was a "rock your world" moment at the lab. I now have a small one of those garnets as part of my personal collection.

Wink