Do blue sapphires have fluorescence?

[Sydneyphoenix]

We all love almost magical fluorescence of rubies especially those from Mogok. Do other corundum types, specifically blue sapphires from any location (e.g. Kashmir, Burma, Sri Lanka) have reputation for fluorescent glow as well, and if so what does a fluorescent blue sapphire look like in photo?

 

[lilmosun]

We all love almost magical fluorescence of rubies especially those from Mogok. Do other corundum types, specifically blue sapphires from any location (e.g. Kashmir, Burma, Sri Lanka) have reputation for fluorescent glow as well, and if so what does a fluorescent blue sapphire look like in photo?

Not an expert, but my understanding:

Due to traces in chromium, some blue sapphires can fluoresce red/pink under a short wave UV light. Iron can suppress the fluorescence so this is not true for all blue sapphires. And because the chromium content is lower than in rubies, blue sapphires do not glow/fluoresce in natural lighting to my knowledge. Also the ability to fluoresce or not, is not an indication of a stone being heater or not. Not sure about geography but I've seen both African and Ceylon sapphires fluoresce.

 

[Rfisher]

Fun with Fluorescence!

OK, so this is a fun little game to play with your colored gemstones. All you need is a camera and a loupe with a UV light. (I got mine inexpensively on Etsy from FDJtools in Florida.) What is fun is that stones colored with chromium will fluoresce red, but if they have very much iron (like blue...

www.pricescope.com

There’s some discussed here

 

[Avondale]

what does a fluorescent blue sapphire look like in photo?

It looks like this:


Not all fluoresce due to the reasons already described above. There’s an older thread on fluorescence in blue sapphires here on the forum but I’m on mobile right now and it’s not convenient for me to try to find it. But if you’re on pc, run a quick search, you’re sure to find it right away, and there’s more info in there.

 

[LilAlex]

We have some blues that do and some that don't. I thought I liked fluorescent blues better but I actually don't -- just too small a sample size initially!

All things being equal (and they never are), I prefer fluorescence in sapphires but I now have no good reason for this bias.

Since you mentioned it, "glow" is very different from fluorescence, except maybe in rubies and pink/red spinel where the fluorescence amplifies the body color. In sapphires, glow usually pertains to white-light-scattering by rutile needles that makes the stone light up like a colored LED.

 

[Avondale]

There’s an older thread on fluorescence in blue sapphires here on the forum

Figured I'd go get it now that I have time. Here it is, lots of info in here: https://www.pricescope.com/communit...ed-fluorescence-in-blue-sapphire-mean.172562/

We have some blues that do and some that don't. I thought I liked fluorescent blues better but I actually don't -- just too small a sample size initially!

This got me curious - would you mind sharing the common qualities of your fluorescent sapphires? At least I imagine there are some. Up until now I thought fluorescence in blue sapphires was more or less a cool gimmick, not so much something that actually affected the visual appearance of the stone. The ring I posted above, I didn't even know it fluoresces when I bought it, found out accidentally while playing with the uv torch.

 

[LilAlex]

This got me curious - would you mind sharing the common qualities of your fluorescent sapphires? At least I imagine there are some. Up until now I thought fluorescence in blue sapphires was more or less a cool gimmick, not so much something that actually affected the visual appearance of the stone.

Well, again, not a huge sample size, unfortunately. For work, I spend a lot of time outdoors under cloudy skies and the ones I like best are vivid under these conditions. I thought it was fluorescence but it is something else; UV is blocked by clouds (not all of it) and I think it is mostly the "soft box" effect of diffused overhead light.

I thought the fluor ones were more "electric blue" looking but I no longer think there is a correlation.

I am a bit of an outlier in preferring the look of blue sapphires under bright cloudy skies but it is super-obvious where I live and the only other sapphire-wearer I know agrees -- even though vendors think I am nuts.

 

[Avondale]

I thought it was fluorescence but it is something else; UV is blocked by clouds (not all of it) and I think it is mostly the "soft box" effect of diffused overhead light.

I thought the fluor ones were more "electric blue" looking but I no longer think there is a correlation.

I see. So fluorescence remains just a cool gimmick. For now, at least.

I am a bit of an outlier in preferring the look of blue sapphires under bright cloudy skies

I believe I might be in the same camp. Direct sunlight is sometimes great but sometimes closes them off. Cloudy skies always produce a lovely result.

 

[shelovesinclusions]

I am a bit of an outlier in preferring the look of blue sapphires under bright cloudy skies but it is super-obvious where I live and the only other sapphire-wearer I know agrees -- even though vendors think I am nuts.

I agree with you. And they picture so well on those days too.