What does red fluorescence in blue sapphire mean?

[1001smiles]

Hello. I don't mean to add yet another thread on sapphires, but I am really curious about this.

So I got a pretty little sapphire from Ebay yesterday, from a reputable vendor on this forum. It's not "top" color by any means, but I like it. It's on a lighter side and I would guess medium saturation, and it's pretty well cut and looks bright to me. It's kind of slightly greyish-violetish-blue in daylight and shifts more towards violet in incandescent. It wasn't too expensive, so I am ok with it not being top color (in fact, I wanted a lighter one). It was sold as a heat-only, and from Madagascar.

So here is my question. I was very surprized to see that it has red fluorescence under UV. Not as strong as a Mahenge spinel or a ruby, but still very obvious. Why would a blue sapphire have red fluorescence??? (I hope it does not mean something bad like synthetic or diffused).

Thank you in advance for sharing your knowledge here.

 

[T L]

Hello. I don't mean to add yet another thread on sapphires, but I am really curious about this.

So I got a pretty little sapphire from Ebay yesterday, from a reputable vendor on this forum. It's not "top" color by any means, but I like it. It's on a lighter side and I would guess medium saturation, and it's pretty well cut and looks bright to me. It's kind of slightly greyish-violetish-blue in daylight and shifts more towards violet in incandescent. It wasn't too expensive, so I am ok with it not being top color (in fact, I wanted a lighter one). It was sold as a heat-only, and from Madagascar.

So here is my question. I was very surprized to see that it has red fluorescence under UV. Not as strong as a Mahenge spinel or a ruby, but still very obvious. Why would a blue sapphire have red fluorescence??? (I hope it does not mean something bad like synthetic or diffused).

Thank you in advance for sharing your knowledge here.

Sapphires should not fluoresce as far as I know, as the coloring component is iron, and that kills fluorescence. Sounds like a synthetic spinel. Sorry! I hope I'm wrong.

Is it loupe clean? Look too perfect?

Please note that I COULD BE VERY WRONG, as I'm not an expert in fluorescence of gems. I hope someone chimes in that knows more about this.

 

[T L]

Apparently they can have some fluorescence, but its not strong. See this article by Richard Hughes.

http://www.ruby-sapphire.com/heat_seeker_uv_fluorescence.htm

 

[1001smiles]

Thanks, TL. That's what I was kind of worried about. Although it's from one of our favorite vendors here, who I don't think would risk his reputation by selling a synthetic. So I hope there is another explanation for this.
To answer your question, I don't see inclusions, but I do see zoning (especially when the stone is up-side-down).

 

[T L]

Thanks, TL. That's what I was kind of worried about. Although it's from one of our favorite vendors here, who I don't think would risk his reputation by selling a synthetic. So I hope there is another explanation for this.
To answer your question, I don't see inclusions, but I do see zoning (especially when the stone is up-side-down).

If there's zoning, then it's less likely a spinel. I have never ever seen zoning in a spinel (natural or synthetic). It could be high heat treatment that caused the fluorescence, according to the article. If it glows bright red under UV light, then I would worry more, but you said it wasn't strong fluor.

 

[1001smiles]

Apparently they can have some fluorescence, but its not strong. See this article by Richard Hughes.

http://www.ruby-sapphire.com/heat_seeker_uv_fluorescence.htm

Thanks again. I think we posted at the same time.
I did find this article last night when I was trying to search the web for a possible explanation. But I think they are referring to "chalky" bluish fluorescence in blue sapphire, not red fluorescence. Maybe I missed it...

 

[T L]

I'll ask around for you and let you know if I find anything out.

 

[1001smiles]

Here's a picture, it was really hard to get the fluorescence photo...
So front view, back view showing zoning and faint red fluorescence (although it looks brighter red in real life, my camera could not capture it).
Any more info is much appreciated.
Thanks.

 

[T L]

I just had to order a new UV light, but if people want to check their sapphires also, that would help, especially if they have a lab report deeming them only heated. My last UV light just died. I will check mine when I get it, and I put the question out there to the gemological community.

Very interesting! Very pretty stone, so I hope there's nothing fishy with it.

ETA: What is the origin of the stone? That might help too, if there's a certain locale producing this fluorescence.

 

[1001smiles]

I just had to order a new UV light, but if people want to check their sapphires also, that would help, especially if they have a lab report deeming them only heated. My last UV light just died. I will check mine when I get it, and I put the question out there to the gemological community.

Very interesting! Very pretty stone, so I hope there's nothing fishy with it.

ETA: What is the origin of the stone? That might help too, if there's a certain locale producing this fluorescence.

Thanks for checking, TL. Did you ask on GO? Are you allowed to put a link here? I'd be curious what they say.

The stone is from Madagascar, heated. I'll just go ahead and say that it's from Tan (you probably guessed that based on the cut). I really don't think Tan would sell anything "fishy". But I am curious to know the scientific explanation for this...

 

[T L]

I just had to order a new UV light, but if people want to check their sapphires also, that would help, especially if they have a lab report deeming them only heated. My last UV light just died. I will check mine when I get it, and I put the question out there to the gemological community.

Very interesting! Very pretty stone, so I hope there's nothing fishy with it.

ETA: What is the origin of the stone? That might help too, if there's a certain locale producing this fluorescence.

Thanks for checking, TL. Did you ask on GO? Are you allowed to put a link here? I'd be curious what they say.

The stone is from Madagascar, heated. I'll just go ahead and say that it's from Tan (you probably guessed that based on the cut). I really don't think Tan would sell anything "fishy". But I am curious to know the scientific explanation for this...

No, I asked somewhere else (I don't like asking anything on that place you mention as I usually don't get the answers I need). I also emailed AGL about it.

 

[1001smiles]

Thanks so much for checking, TL!

 

[partgypsy]

I don't know what it means in your case,
but I swear I was looking at a blue sapphire that came with a grading report (I can't remember if GIA or AGL) that showed it had flourescence in the red wavelengths. I never ended up buying it, but at least for that stone it seemed to indicate that natural blue sapphires can flouresce red.

 

[partgypsy]

Aha! found the thread.

[URL='https://www.pricescope.com/community/threads/blue-sapphire-cert-question.60551/?hilit=blue%20sapphire']https://www.pricescope.com/community/threads/blue-sapphire-cert-question.60551/?hilit=blue%20sapphire[/URL]

 

[1001smiles]

Aha! found the thread.

[URL='https://www.pricescope.com/community/threads/blue-sapphire-cert-question.60551/?hilit=blue%20sapphire']https://www.pricescope.com/community/threads/blue-sapphire-cert-question.60551/?hilit=blue%20sapphire[/URL]

Thanks, Gypsy. Nice to see other examples out there.

 

[beaujolais]

chromium
lots about it, if you do a Google search
I've got a violet sapphire that has a big red fluorescence.

 

[1001smiles]

I thought chromium makes things red, like ruby or pink/purple sapphire. So you think there is enough chromium in blue sapphire to account for this much fluorescence? Maybe that's what gives it a bit of violetish hue...

 

[T L]

From the head gemologist of AGL, Christopher Smith.

"Blue sapphires may indeed fluoresce. Although iron will suppress fluorescence, if there is enough chromium a stone will have a red/reddish fluorescence reaction to LWUV. If you have other elements such as magnesium, a sapphire may have an orangey fluorescence reaction. Depending on the distribution of these elements, the fluorescence could be in bands or zones, as well as throughout. In some heated sapphires you may also observe a whitish or chalky fluorescence reaction to SWUV."

Hope that's good news, but if you're really worried, I would send the stone to AGL for testing.

 

[Pandora II]

I have a blue sapphire that I know 100% is a natural sapphire and is low heat only.

I got a bit of a shock when running a uv light over a case of stones to see this blue sapphire glowing red... so I took it out for a closer look.

The stone is a violet blue and close examination showed that some of the very fine colour zones (not visible to the naked eye) were actually a pink colour - hence why the stone was quite violet. It was these zones that were fluorescing.

 

[1001smiles]

Thanks very much for the info, TL. That's interesting to know.
I wasn't too worried since Tan hasn't given us much reason to worry. But I was more curious... I don't think this stone is expensive enough to invest in a cert. Although I live next town to GIA and this might be a good excuse to go check them out...
Anyways, thanks again.

 

[T L]

Thanks very much for the info, TL. That's interesting to know.
I wasn't too worried since Tan hasn't given us much reason to worry. But I was more curious... I don't think this stone is expensive enough to invest in a cert. Although I live next town to GIA and this might be a good excuse to go check them out...
Anyways, thanks again.

NP, I was really curious myself. I guess you learn something new every day.

 

[chrono]

I thought chromium makes things red, like ruby or pink/purple sapphire. So you think there is enough chromium in blue sapphire to account for this much fluorescence? Maybe that's what gives it a bit of violetish hue...

There is also chromium in colour change spinels (responsible for the shifting of hue) and emeralds.

 

[Silvia]

That looks awesome! Can you post a link to the supplier? I want one!

 

[Pandora II]

Sapphires should not fluoresce as far as I know, as the therapy element is precious metal, and that lowers fluorescence. Seems to be like a artificial spinel. Sorry! I wish I'm incorrect. Diamond Rings | Engagement Rings | Diamond Engagement Ring

You are incorrect.

I'm not sure what you mean by 'therapy element', but the chromophores in blue sapphire are generally titanium and iron, BUT sometimes they will also contain trace amounts of chromium which does fluoresce.

 

[chrono]

Rickyswann,
I'd like to know where you got the information; it is listed in notable books/websites that some sapphires contain traces of chromium, hence will fluoresce pink/red but not strongly.

 

[colorluvr]

From the head gemologist of AGL, Christopher Smith.

"Blue sapphires may indeed fluoresce. Although iron will suppress fluorescence, if there is enough chromium a stone will have a red/reddish fluorescence reaction to LWUV. If you have other elements such as magnesium, a sapphire may have an orangey fluorescence reaction. Depending on the distribution of these elements, the fluorescence could be in bands or zones, as well as throughout. In some heated sapphires you may also observe a whitish or chalky fluorescence reaction to SWUV."

Hope that's good news, but if you're really worried, I would send the stone to AGL for testing.

Thanks so much for sharing this email with us.

 

[chel180]

I was just browsing thru sapphires listings and saw a 3.06ct purple oval sapphire with GiC certificate that also has red fluorescence (also pink), about half way down. I'd never heard of a sapphire with fluo before but now I've heard of two.
http://sapphires.ca/Unheated%20Pink%20Sapphires%20win.htm

 

[deorwine]

I have a blue sapphire that I know 100% is a natural sapphire and is low heat only.

I got a bit of a shock when running a uv light over a case of stones to see this blue sapphire glowing red... so I took it out for a closer look.

The stone is a violet blue and close examination showed that some of the very fine colour zones (not visible to the naked eye) were actually a pink colour - hence why the stone was quite violet. It was these zones that were fluorescing.

Pandora, I have to say this is wicked cool.

 

[minousbijoux]

I second that! Pandora, does that mean that my blue sapphire with a violet modifier has layers of pink in it not visible to the naked eye as well? I can't see any with my loupe, but I would LOVE that! How cool would that be?!

 

[LD]

Quite a number of colour shifting sapphires exhibit weak fluoresence and I also have a Padparadshca that exhibits a stronger fluor.