[Rockhounds] REE, calcite, and lost and hidden secrets of the stones...

[Axel Emmermann]

 Hi Pete & all.

I wrote:
> If I  remember correctly it 's cerium(/lead?) + 
> manganese/lead that cause  the pink fluorescence in long wave 
> UV and cerium =>europium that are  responsible for the blue 
> phosphorescence in short  wave.

And then you wrote:

> And, Axel, I think you are going beyond anything that is 
> definitely known here.  Yes, it has been hypothesized that 
> europium is "probably" the cause  of the blue fluorescence 
> and phosphorescence, but that's about it I think, as  far as 
> real knowledge.  

And then I write again:
Absolutely. I know remember that I read about Glen Waychunas having
researched this type of material and I believe that the conclusion was
indeed a "probable" or something along those lines. It was also a slip of
the keyboard ;-)) I should have phrased it more like "If I  remember
correctly it 's BELIEVED TO BE cerium(/lead?) + manganese/lead etcetera...
I beg extensive pardons from everybody all over the place. I'm usually more
careful. 

>Other minerals that fluoresce due to 
> europium (such  as
> fluorite) fluoresce LW rather than short, 

Yes, but wasn't there something said about the blue fluorescence actually
NOT being fluorescence but phosphorescence caused by energy transfer
(electrochemically) between cerium and europium?  
You can actually see the ph coming up if you flash a SW light over a
TT-calcite. Short pink burst and then it turns blue. I have REE-doped
ceramics that behave the same way but slower (red-pink to blue over a period
of several seconds).

> and do not 
> phosphoresce; and Mn/Pb produces the common red/orange fl. in 
> calcite, but that's quite unlike the pink  LW of 
> Terlingua-type calcite.

Not if you shine a REALLY REALLY LW source on it. Under 390 nm all my
TT-calcite glows orange red... The shorter the wavelength the stronger the
blue PH gets. At 350 nm you get a few specimens that fluoresce straw-yellow
to pink and at 320 nm some specimens are nearly white.

> So I still think everybody is just 
> guessing at this.  I know a few people have played around 
> with some research on  this, but I don't think anything 
> formal or conclusive has ever been published--again, I'd LOVE 
> to know that I am wrong, and I would love it if  anyone could 
> direct us to any actual published articles giving hard data 
> about  this type of calcite!

Yeah, I'd love to know too ;-)))
  
Cheers
Axel