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 Post subject: Mint garnets and orange fluorescence
PostPosted: Thu Jun 04, 2009 9:48 pm 
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My mint grossular garnet fluroesces a very deep orange color - never seen anything fluoresce this color before. Does anyone know why, or what element in the stone may contribute to this? Do tsavorites fluoresce orange?


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PostPosted: Thu Jun 04, 2009 10:37 pm 
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I've noticed this several years ago. I did once try longwave UV on a med-dark (5/6 G) Tsav and it was pretty inert as far as fluorescence goes...


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PostPosted: Thu Jun 04, 2009 11:10 pm 
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hi tudortwo

A couple weeks ago, Bear Williams showed me a picture and graph of a tsavorite fluorescing red, with the absorption band closer to 400nm than to 350nm. The red fluorescence is due to chromium, which also gives rise to the green body color. I don't know about orange fluorescence, though.


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PostPosted: Thu Jun 04, 2009 11:53 pm 
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It's like a deep neon orange color, and I can't figure out why it does this.


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PostPosted: Fri Jun 05, 2009 9:24 pm 
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Brian wrote:
hi tudortwo

A couple weeks ago, Bear Williams showed me a picture and graph of a tsavorite fluorescing red, with the absorption band closer to 400nm than to 350nm. The red fluorescence is due to chromium, which also gives rise to the green body color. I don't know about orange fluorescence, though.


Vanadium???


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PostPosted: Sat Jun 06, 2009 1:03 am 
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I dunno. I have never found spectroscopic evidence that is associated with vanadium. I would like to possess a known vanadium sample, so that clearly, I could put it through my standard tests, but I don't have it.


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PostPosted: Sat Jun 06, 2009 10:14 am 
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Strong fluorescence in rubies can sometimes be on the verge of "neon orange" as there is a orange tint to the red fluorescence. It can by some people be described as orange. This has happened to me when showing ruby fluorescence to friends who have never seen it before. They have said "oh what an intense orange".
By this I suggest the mint grossular might have a chromium fluo. Tudortwo have you checked the spectrum of this particular stone?

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PostPosted: Sat Jun 06, 2009 10:55 am 
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Excellent advice, Connie!


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PostPosted: Sat Jun 06, 2009 2:32 pm 
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Conny Forsberg wrote:
Strong fluorescence in rubies can sometimes be on the verge of "neon orange" as there is a orange tint to the red fluorescence. It can by some people be described as orange. This has happened to me when showing ruby fluorescence to friends who have never seen it before. They have said "oh what an intense orange".
By this I suggest the mint grossular might have a chromium fluo. Tudortwo have you checked the spectrum of this particular stone?


Hi Connie. BTW, thanks for those spinel microphotographs. Nice to see you over here. GO is very suited to your expertise I might add.

I am not a gemologist, so I do not have the equipment to check the spectrum, nor do I know how. My only tools are a chelsea filter, some loupes, and my UV light. I know, quite pathetic for a colored gem collector. :oops:


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PostPosted: Sat Jun 06, 2009 4:03 pm 
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That is more than I have... I ought to pick up a Chelsea filter one of these days. I do have an ASET and IdealScope, but those arent as helpful with colored stones.


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PostPosted: Mon Jun 08, 2009 8:54 am 
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Conny, are you Cofor?

I too need to get a move on getting my UV light. I'd love to check my tsavorite and green grossular garnet (mint) for flouroscence.


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PostPosted: Mon Jun 08, 2009 9:00 am 
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Chrono,
If you need equipment, this ebayer seems to have very good prices.

http://myworld.ebay.com/opticfactory

I bought my chelsea from them. I got my uv light from another seller, but I forget who that was from ebay, but they're all over ebay for rather cheap.


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PostPosted: Mon Jun 08, 2009 1:29 pm 
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Chrono wrote:
Conny, are you Cofor?


Yes Chrono, I confess :-)

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PostPosted: Mon Jun 08, 2009 1:36 pm 
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Conny Forsberg wrote:
Chrono wrote:
Conny, are you Cofor?


Yes Chrono, I confess :-)


i'm missing something? :roll:

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PostPosted: Mon Jun 08, 2009 1:54 pm 
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No, Alberto, it's nothing alarming. I only just realized that Conny is Cofor elsewhere and I enjoy her pepto bismol macro photography of spinels.


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