Workgroup    Fluorescence
Phosphates - Arsenates - Vanadates
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Adamite: Ojuela Mine, Mapimí, Mun. de Mapimí, Durango, Mexico

A tiny bit of uranyl ions causes this fluorescence.
Short wave UV
Ambligonite: Tanco Mine, Bernic Lake, Lac-du-Bonnet area, Manitoba, Canada

The cause of this fluorescence is yet unknown.
 
 
Austinite: Gold Hill Mine, Gold Hill, Gold Hill District, Deep Creek Mts, Tooele Co., Utah, USA

The green fluorescence is caused by a litlle uranyl.
White light and short wave UV
Autunite: TL, near Autun,  Saône-et-Loire, Burgundy, France.

The fluorescence is intrinsic. Many uranyl minerals fluoresce yellow to green. A fairly large number of them do that only when they are cooled to cryogenic temperatures. Autunite is one of the brightest fluorescent minerals.
White light and long wave UV
 
Short wave UV
Apatite in Jumillaite: Jumilla, Murcia, Spain

Jumillaite is not a mineral, it is a mixture of calcite, analcime, leucite and other hydrothermally formed minerals in the volcanic rock of Jumilla. This mixture fluoresces white to very light sky blue. The apatite fluoresces an attractive orange-pink due to the the presence of numerous elements from the lanthanides (rare earth elements).
 
Apatitte: Morro Velho mine, Nova Lima, Iron Quadrangle, Minas Gerais, Brazil

Fluorescence due to presence of rare earth elements.
 
 
Apatite: Medina, Jequitinhonha vallei, Minas Gerais, Brazil

Fluorescence due to presence of divalent manganese and rare earths that replace calcium.
White light and short wave UV
White light and short wave UV
Short wave UV
Apatite: Golconda mine, Golconda district, Coroaci, Doce valley, Minas Gerais, Brazil

This apatite crystal shows different fluorescent colors depending on the UV wavelength it's bombarded with. This is because different activators only react to specific excitation energies. The crystal is between 2 and 3 mm wide.
Apatite normal light
Apatite long wave UV
Apatite Midrange UV
Apatite SW-UV
 
Tyuyamunite:
Margaritas No. 1 Mine, Sierra Peña Blanca, Peña Blanca District, Mun. de Aldama, Chihuahua, Mexico

One of many yellowish green fluorescing minerals. See spectra for details.
Halogen light and 405 nm violet laser resp.
 
 
Wavellite:

Kielce District, Świętokrzyskie Mts (Holy Cross Mts), Świętokrzyskie, Poland

Dark brown spherical aggregate on white quartz. The brown color is most likely caused by included tar and other organic materials. It's those materials that cause the fluorescence too.
Halogen light and 405 nm violet laser resp.
Adamite
Ambligonite
Austinite
Autunite
Fluorapatite
Fluorapatite
Fluorapatite
Fluorapatite
Tyuyamunite
Wavellite
Pyromorphite
Pyromorphite Pb5(PO4)3Cl

Yangshuo mine, Yangshuo Co., Guilin, Guanxi Province, China

This mineral usually responds better to short wave UV when lead and elements of the lanthanides group are present. We then see a broadband peak of lead and/or cerium in the middle range of the UV. The lanthanides, or rare earths as we call them, then show clearly recognizable sharp and well defined peaks. However, this specimen clearly responds better to long wave UV. We see a broadband emission that centers around 560 nm. Two authors give different explanations:

Gaft: replacement of (PO4)3-  by (VO4)3-  . Vanadium  is found in the mine in the form of descloizite, PbZn (VO4)(OH), which supports this theory.

Gorobets & Rogojine: by analogy with the empirically assumed fluorescence of monovalent silver in baryte, these authors name Ag+  as an activator for this mineral. However, there are no silver minerals on the inventory list of this mine. On the other hand... where lead and zinc occur, silver is usually not far away.
Pyromorphite in halogen light
Pyromorphite in MW UV
Pyromorphite fluorescence in LW UV (365 nm LED)
Emisionspectrum under 365 nm LED source
 
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Swedenborgite in calcite
 
Water clear swedenborgite crystal in calcite matrix
Strong  fluorescence in short wave UV
Spectrum with insets of the spectra of the calcite matrix
Comparative spectra of swedenborgiet and other titanium bearing  minerals
Swedenborgiet, Långbån, Sweden

Swedenborgite is hardly distinguishable from the calcite in which it occurs without a short wave UV source. It forms hexagonal crystals that can only be distinguished from the matrix because they are water clear. In order to explain the fluorescence, we first need to look at the composition of the mineral: NaBe4Sb5+O7.
Beryllium is far too small to be replaced by one of the ‘usual’ activators. Sodium is sometimes replaced by manganese, but manganese can only fluoresce between red and green (in fluorite where it can replace Ca). Blue is not in its ‘palette’. According to an article by Michael Gaft, H. Yeates and Lev Nagli in the European Journal of Mineralogy: Laser-induced time-resolved luminescence of natural margarosanite Pb(Ca,Mn)2Si3O9, swedenborgite NaBe4SbO7 and walstromite BaCa2Si3O9, the presence of trivalent antimony may be responsible for the blue fluorescence. However, they express themselves very carefully and I quote: " such luminescence behavior is typical for s2 ions, such as Sb3+. In swedenborgite Sb presents in +5 state, which is not luminescent. If the minute presence of Sb3+ may be supposed, it is the mostly probable luminescence center." (see also Michael Gaft,  Renata Reisfeld, Gerard Panczer  (2015) Modern Luminescence Spectroscopy of Minerals and Materials, Second Edition).

A real 'if then else' but Sb3+  is a well-known activator in synthetic phosphors. In calcium halophosphates (apatites) it is a highly efficient activator with blue emission. It is also a strong activator in YPO4:Sb3+.  So it seems that the massive emission peak at 410 nm has been declared with great probability.
However, there is still a small peak at 480 nm that needs explanation. After some research in my library of spectra, I found a number of titanium-bearing minerals with similar emissions. The [TiO6]8- ion  causes the blue fluorescence of, among other things, benitoite, diopsite and dumortierite. There is also enough space in the swedenborgite crystal lattice to allow the Sb5+  ion to be replaced by Ti4+.  To this end, however, compensation must be found for the charge differences between Sb5+  and Ti4+. This could be done by replacing some Na+  with Ca2+. Chemical analysis shows that 0.68 % CaO was present in the analysed specimen. (Danielle M.C. Huminicki and Frank C. Hawthorne, Refinement of the crystal structure of swedenborgite, February 2001The Canadian Mineralogist 39(1):153-158).  In the end, only a very small amount of Ti4+ is needed (100-1000 ppm) to get fluorescence. This is likely to be below the detection limit of the analysis performed. The attached spectrum shows Ti4+  emission in talc and dumortierite for comparison. Please note: this is not an established fact but my personal suggestion, supported by the presence of calcium in the swedenborgiet studied. Incidentally, no less than a dozen titanium-containing minerals are found in the Långbån locality.
However, we must not forget that Eu2+  is also a possibility. Europium in a divalent state can cause a whole range of fluorescence colors depending on the strength of the crystal field in the mineral concerned. To find out whether it is titanium or europium that causes this peak, one would need a spectrometer that measures half-life, the "τ" tau, of the fluorescence. The luminescence of Eu2+  expires in a time span of 600 - 800 nanoseconds, that of [TiO6]8- takes about 10 μsec. They would thus be easily distinguishable. Unfortunately, such a gated spectrometer is far beyond the financial capacity of mineral collectors and their clubs.
For what concerns the rest of the spectrum: all other emissions of the spectrum belong to the surrounding calcite. That shows lead, manganese, samarium and europium. The swedenborgite crystal is barely a few millimeters wide and water clear. It is therefore unavoidable that the fluorescence of the calcite matrix is shining through and slightly photo-bombing matters. 

Acknowledgement: many thanks to Glenn Waychunas for reviewing the above text and sharing his insights.
Copyright © 2014 by Axel Emmermann  ·  All Rights reserved  ·  E-Mail: fluorescentie@minerant.org
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