My violet sapphire flouresces red (?)

[beaujolais]

I just found out that my violet sapphire flouresces red. Cool but I read that heat treated sapphires flouresce "chalky green"?

What do you think this is?

Thanks.

 

[Richard M.]

I don''t believe "chalky green" fluorescence is anything but an indication of heat treatment. The test should be performed carefully under controlled conditions as described here: Fluorescence

Were you using Short Wave ultraviolet? Does the color of your stone resemble that in Figure 13? Was the stone very clean?

It''s an interesting question. Maybe you should take the stone to an experienced gemologist.

Richard M.

 

[coatimundi_org]

Do you know the origin of your stone? Blue sapphires do not often fluoresce, because they are often found in iron rich basalt. If it formed in metamorphic (marble) rock it would not have the iron to inhibit its fluorescence.

Sapphires from Sri Lanka and part of Madagascar are formed in some types of metamorphic rock--less iron to inhibit fluorescence. Wonder what element creates that color? Chromium causes red fluor in rubies. Anyone know what could cause it in sapphire?

 

[beaujolais]

Thanks Richard & Coati:

I just looked on it's papers and I need to correct my previously saying it was heat treated. The papers say "enhancements: none". So, not heat treated. It's from Sri Lanka. Slightly included, looks eye clean though. Yes, it looks like Fig. 13.

I looked at it with this uv flashlight:

http://www.amazon.com/Professional-UV-Inspection-Flashlight-Aluminum/dp/B0013E3XVU/ref=pd_bbs_sr_3?ie=UTF8&s=sporting-goods&qid=1218093446&sr=8-3

Not sure if this is short or long wavelegnth. Please tell me, if you know.

Thanks so much.

 

[coatimundi_org]

The light you bought is long wave.

Not heat treated from Sri Lanka--I'd say you lucked out with that interesting fluor--and made a good choice in a stone. I'm partial to their mining methods. The slightly included is probably from fine rutile needles (silk)--sounds beautiful. Do you have a photo?

My guess is that it got its fluor from the way it formed--without iron to inhibit it--in a metamorphic rock like marble.
I really want to know what transitional element is causing the fluor.
I'll ask my instructor at school today.

If you were in Los Angeles--you could bring your stone over to GIA, and my instructor could have a go at it--just a fun thought.

 

[Proteus]

It''s not unusual for a violet sapphire to fluoresce red. Color change sapphires may fluoresce red as well. It is probably from traces of chromium, which is what causes the fluorescence in ruby. Violet sapphires can contain chromium.

 

[Richard M.]

Coatimundi and Proteus,

If you followed my link you should have discovered the following photo (13) caption by Hughes:

"One of the remaining corundum mysteries is the cause of the "apricot" orange fluorescence seen in many sapphires of both blue and yellow color, particularly those from Sri Lanka and Madagascar. This fluorescence may be seen in both LW and SW, with LW always being stronger, and is unaffected by heat treatment. The above stone is an untreated Madagascar blue sapphire in LW, the same stone as shown in Figures 11 and 12. Note that the culet area, which contains the heaviest concentration of blue color, is inert."

Sonomacounty says his/her unheated stone looks like Fig. 13 in LW.

If formational modes, including the presence of iron or chromium, were responsible for the fluorescence, I''m sure Richard Hughes and John Emmet would say so. They are among the world''s foremost researchers on corundum. They call such fluorescence a "mystery."

Richard M.

 

[Proteus]

Interesting - I haven''t come across any of these mystery fluorescent sapphires before. But, that is a blue sapphire in figure 13, and Sonomacounty''s is violet, correct?

I know that violet coloration can be caused by chromium impurities, so I suggested chromium. Hughes and Emmet didn''t say specifically if the apricot fluorescence occurs in anything other than blue and yellow, which creates some ambiguity. Is your sapphire a true violet color, or a violetish-blue? The difference may be significant to the cause of the fluorescence.

But either way, it''s perfectly normal.

 

[beaujolais]

Thanks all.

It's papers list it as "light bluish violet", although I think it's more medium than light. (I don't see much blue in it, though. It's not lavender, not purple, more a medium violet - just to describe it for you.)

I don't have a photo, Coati, as my digital camera doesn't have macro. Thanks for asking, though. Hope your studying is going well. It sounds like you really enjoy it. You will be one fine G.G. Oh, I live in NY now (used to live in CA) so L.A. is a bit far. Thanks, though.

Thanks, everyone, for all your ideas and knowledge. You are just a wealth of info and great people.

I've had this for awhile and never looked at it with the UV light, although have looked at most of my other stones, as I thought, well sapphires don't flouresce. And, well, surprise . . .

 

[topcatskin]

Richard/all,
do you interpret the article to mean that if a sapphire floureces orange/red that the stone has NOT (or unlikely) been heat-treated?
thanks.
R/

 

[coatimundi_org]

Date: 8/7/2008 1:21:44 PM
Author: Richard M.
Coatimundi and Proteus,


If you followed my link you should have discovered the following photo (13) caption by Hughes:


'One of the remaining corundum mysteries is the cause of the 'apricot' orange fluorescence seen in many sapphires of both blue and yellow color, particularly those from Sri Lanka and Madagascar. This fluorescence may be seen in both LW and SW, with LW always being stronger, and is unaffected by heat treatment. The above stone is an untreated Madagascar blue sapphire in LW, the same stone as shown in Figures 11 and 12. Note that the culet area, which contains the heaviest concentration of blue color, is inert.'


Sonomacounty says his/her unheated stone looks like Fig. 13 in LW.


If formational modes, including the presence of iron or chromium, were responsible for the fluorescence, I'm sure Richard Hughes and John Emmet would say so. They are among the world's foremost researchers on corundum. They call such fluorescence a 'mystery.'


Richard M.

I did follow the link. I thought sonoma described her fluor as red, not apricot. I missed that she said it resembled the stone in that photo--thanks for clarifying.

Apricot is a mystery. Red is not. Chromium causes red fluorescence in ruby so it follows that it would cause red in other colored corundum--like Proteus stated--I just wanted to know for sure--about red specifically. Not much to say about apricot if eminent researchers call it a mystery! -but I would love to know.

Proteus-thanks for the info--we are actually in the middle of the corundum section of colored gems. I have much to learn!

Sonoma, so your stone's fluor is more apricot than red? If so--how interesting--and rare!

topcatskin-the stone in figure 13 has not been heat treated.

 

[Richard M.]

Date: 8/7/2008 8:13:54 PM
Author: topcatskin
Richard/all,

do you interpret the article to mean that if a sapphire floureces orange/red that the stone has NOT (or unlikely) been heat-treated?

thanks.

R/

The authors are saying orange/red fluorescence occurs in both heated and unheated blue and yellow sapphires so is not an indication of either treatment or natural, as I read it.

Richard M.

 

[Catmom]

My color change sapphire is unheated and it fluoresces red under a blacklight.