Database of luminescent minerals 

FLUORITE

Chemical formula: CaF₂

Family: Halides

Status: IMA-GP

Crystal system : Isometric

Display mineral: OUI

Associated names (luminescent varieties, discredited names, synonyms, etc.): chlorophane,  yttrofluorite,  yttrocerite,  Tiffany stone,  fluorine, 

Luminescence:

Daylight picture

FLUORITE;
Blue Circle Cement Quarry, Eastgate, Weardale, North Pennines, County Durham, England, UK
Photo and Copyright:
Middleearthminerals.com
Used with permission of the author

Longwave (365nm) picture

FLUORITE;
Blue Circle Cement Quarry, Eastgate, Weardale, North Pennines, County Durham, England, UK
UVLW, Photo and Copyright:
Middleearthminerals.com
Used with permission of the author

Pictures Galery:

  
  Go to the galery (35 pictures)

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Phosphorescence (in the common sense of the term) observable with the naked eye:

Triboluminescence: OUI

Thermoluminescence: OUI

Comments:

The classical fluorescing mineral but all fluorites are not luminescent under UV !

CHLOROPHANE variety : green thermoluminescence ;

YTTROFLUORITE variety: SW and LW : yellow, yellowish-white (cream);

Activator(s) and spectrum:

Activator(s): Eu²⁺, ST (Singlet-triplet)-Matière organique en impureté,  Sm²⁺,  Ce³⁺,  Sm³⁺,  Eu³⁺,  Dy³⁺,  Ho³⁺,  Er³⁺,  Tb³⁺,  Pr³⁺,  Nd³⁺,  Yb³⁺,  Tm³⁺,  

Peaks in the spectrum (nm):

Eu²⁺ repl. Ca²⁺: 423-425nm (associated with deep blue-violet fluorescence)
Sm²⁺ repl. Ca²⁺: 708, 733nm
Yb²⁺ repl. Ca²⁺: 550nm
Dy³⁺:468, 478, 575, 654, 658, 663, 671, 685nm
Tb³⁺:482, 484, 486, 492, 539, 543, 544, 546, 583, 588nm
Er³⁺:519, 522, 528, 551, 554nm
Sm³⁺:561nm
Eu³⁺: 574, 595, 618, 622, 700nm
Nd³⁺: 920nm
M-center(2F+Na⁺): large pic at 720-745 nm
M_A center charge stabilized by O²⁻–F⁻  : 690 nm 
M_A center charge stabilized by Na⁺–Ca²⁺ : 750nm

Spectrum: Michael Gaft, Petah Tikva, Israel. Plot: Institute of Mineralogy, University of Vienna, Austria, with permission of the authors.

Spectrum Galery:

  
  Go to the galery (21 spectra)

Comments on spectrum and activators:

Violet fluo associated with Eu²⁺ (420-423 nm) with peaks at 320 and 340nm (Ce³⁺),  decay time of Eu²⁺ is 600–800 ns
yellow fluo associated with Dy³⁺;
M-center: large pic at 720 nm;
Lifetime: 2μs ( @420nm);

λ_ex = 415 nm is most suitable for measuring the Ho³⁺ emission beside the Er³⁺. 

Fluorite was one of the first mineral substances being investigated by George G. Stokes in 1852, hence the name fluorescence given at the phenomenon.

Fluorite is a reservoir for many of the rare earth elements. As early as 1881, it was pointed out that Cerium was present in fluorite.

In 1906, Urbain studied the cathodoluminescence of fluorite and ascribed the cause of fluorescence to RRE (Yttrium, praeseodymium, samarium, dysprosium, europium, terbium and also gadolinium and Ytterbium in chlorophane); Morse (1907), Tanaka (1924), Nichols (1928) and F. G. Wick also investigated the cause of luminescence of fluorite. 

The fusion of fluorescent fluorite (1100-1200°C) changes the spectrum markedly. Often the blue luminescence spectrum is changed to a more orange-red, showing sharp lines typical of RRE.

De Ment makes 2 groups in the luminescent fluorites:

group 1: single band in the UV at 300nm and 3 bands in the visible at 475, 508 and 578nm
group 2: two bands in UV at 280 and 300nm and strong peaks at 475, 510, 536, 548 and 578nm in the visible.

Radiation induced M_A centers’ charge stabilized by Na⁺–Ca²⁺ is responsible of emission at 750nm and O²⁻–F⁻ at 690 nm) (Tarashchan 1978, Gaft and Al. 2020).

Best localities for fluorescence (*):

• Rogerley Mine, Weardale, County Durham, England;
• Alston Moore, England;
• Dalnegorsk, Primorskiy Kray, Russia;
• Seilles, Andenne, Prov. de Namur, Belgium (LW fluo red);
• Hunza Valley, Gilgit District, Pakistan;
• Braldu Valley, Skardu District, Gilgit-Baltistan, Pakistan (green SW+LW+Phospho);
• Yuno, Shigar District, Gilgit-Baltistan, Pakistan (green SW with fluorapatite in quartz and microcline);
• Mapimi, Durango, Mexico (SW dull red, LW red);
• Hammam-Zriba Mine, Zriba-Village, Zaghouan Governorate, Tunisia (buish-white LW);
• Rosiclare, Illinois, USA;
• Clay Center, Ohio, USA (yellow-white LW + phosphorescence);
• Yuma County, Arizona, USA;
• Fourmile Creek Area, Fremont Co., Colorado, USA (LW blue + SW & MW green)
• Berta Mine, El Papiol, Barcelona, Spain;
• Villabona Mine, Llanera, Asturias, Spain;
• Xianghualing Sn-polymetallic ore field, Linwu Co., Chenzhou, Hunan, China (blue + red fluo LW);
• Sanming, Fujian, China (blue LW with temporary red fluorescence disappearing after a few seconds);
• Taourirt, Taourirt Province, Oriental Region, Morocco (temporary LW red fluorescence disappearing after a few seconds and comming back after a few minutes without UV);
• Aouli, Upper Moulouya mining district, Midelt Province, Drâa-Tafilalet Region, Morocco (yellow cubes SW white, LW blue)
• Kharan District, Balochistan, Pakistan (fluo red LW).

(*)The data are not exhaustive and are limited to a few remarkable localities for fluorescence

Bibliographic reference for luminescence:

• The Henkel Glossary of Fluorescent Minerals, Dr. Gerhard Henkel, Published by the FMS, 1989 ,
• Fluorescence: Gems and Minerals Under Ultraviolet Light, Manuel Robbins, 1994, Geoscience Press, ISBN 0-945005-13-X ,
• The World of Fluorescent Minerals, Stuart Schneider, Schiffer Publishing, 2006, ISBN 0-7643-2544-2 ,
• Luminescence Spectroscopy of Minerals and Materials, M. Gaft, R. Reisfeld, G. Panczer, Springer Editor, ISBN: 10 3-540-21918-8 ,
• Luminescent Spectra of Minerals, Boris S. Gorobets and Alexandre A. Rogojine, Moscow, 2002 ,
• Ultraviolet Light and Fluorescent Minerals, Th. Warren, S. Gleason, R. Bostwick, et E. Verbeek, 1995, ISBN 0-9635098-0-2 ,
• Franklin Website: http://franklin-sterlinghill.com ,
• Luminescenza nel regno minerale, Guido Mazzoleni, fotografia Roberto Appiani, Libri Sandit, 2010, ISBN 978-88-95990-63-7 ,
• Handbook of mineralogy, John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, and Monte C. Nichols, and published by Mineral Da ,
• The Langesundfjord, history, geology, pegmatites, minerals, Bode Edition, 2010, ISBN 978-3-925094-97-2 ,
• Handbook of Fluorescent Gems and Minerals, a practical guide for the gem and mineral collector, Jack de Ment, 1949 ,

Reference for luminescence on the Internet:

Mineralogical reference on the Internet:

  http://www.mindat.org/show.php?name=Fluorite

  http://webmineral.com/data/Fluorite.shtml

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