Luminescence, fluorescence et phosphorescence des minéraux: fiche descriptive

FLUORITE

Formule chimique: CaF₂

Famille: Halogénures

Statut: IMA-GP

Système cristallin : Cubique

Minéral de vitrine: OUI

Noms associés (variétés luminescentes, noms discrédités, synonymes etc.): chlorophane, yttrofluorite, yttrocerite, Tiffany stone, fluorine,

Luminescence:

Type d'UV	Couleur principale (*)	Intensité	Fréquence d'observation

UV longs (365nm):	Bleu	Très forte	Très souvent
UV moyens (320 nm):	Bleu	Moyenne	Souvent
UV courts (254 nm):	Bleu	Moyenne	Souvent

Autres couleurs OL:	Blanc bleuté , Blanc jaunâtre (crème) , Jaune pâle , Jaune , Brunatre , Rouge , Rose violacé , Vert , Verdâtre , Violet , Blanc verdâtre , Bleu violet , Jaunâtre ,
Autres couleurs OM:	Vert ,
Autres couleurs OC:	Blanc , Blanc bleuté , Blanc jaunâtre (crème) , Jaune pâle , Jaune , Brunatre , Rouge , Vert , Verdâtre , Vert bleu , Violet , Blanc verdâtre , Bleu violet , Jaunâtre ,

(*)Vous pouvez ouvrir la charte des couleurs dans une nouvelle fenêtre

Photo en lumière du jour

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

Photo Ondes longues (365nm)

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

Galerie de photos:

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Accès à la galerie complète (30 images au total)

Phosphorescence (au sens commun du terme) observable à l'oeil nu:

Type d'UV	Couleur	Intensité	Fréquence d'observation
UV longs (365nm):	Blanc verdâtre	Forte	Rarement
UV moyens (320 nm):	Blanc verdâtre
UV courts (254 nm):	Blanc verdâtre

Triboluminescence: OUI

Thermoluminescence: OUI

Commentaires:

Le minéral luminescent classique par excellence, mais attention, toutes les fluorines ne sont pas luminescente loin de là !

Variété CHLOROPHANE : thermoluminescente en vert ;

Variété YTTROFLUORITE : OC et OL: jaune, blanc jaunâtre (crème);

Activateur(s) et spectre(s):

Activateur le plus courant: Eu²⁺

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

Pics dans le spectre (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.

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Vers la galerie de spectres (18 spectres au total)

Commentaires sur les spectres et les activateurs (*):

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).

(*)Les commentaires sur les spectres sont uniquement rédigés en Anglais

Meilleure(s) localité(s) pour la 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);
Morocco (temporary LW red fluorescence disappearing after a few seconds);
Aouli, Upper Moulouya mining district, Midelt Province, Drâa-Tafilalet Region, Morocco (yellow cubes SW white, LW blue)

(*)Les données ne sont pas exhaustives et sont limitées à quelques localités remarquables pour la fluorescence

Référence bibliographique pour la 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 ,