Database of luminescent minerals 

GYPSUM   (French name: GYPSE )

Chemical formula: CaSO₄ 2H₂O

Family: Sulfates

Status: IMA-GP

Crystal system : Monoclinic

Display mineral: OUI

Associated names (luminescent varieties, discredited names, synonyms, etc.): albatre,  selenite, 

Luminescence:

Longwave (365nm) picture

OL (365 nm). Col. G. Barmarin; Photo: G. Barmarin

Shortwave (254nm) picture

OC (254 nm). Col. G. Barmarin; Photo: G. Barmarin

Pictures Galery:

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

Comments:

Syn: selenite;
Sometimes presents a hourglass fluorescing figure in the center of monocrystals first observed in crystals from Wiesloch (Germany) in 1927 by H. Himmel but is now known from many other localities with occurrences of gypsum crystals in clay beds. (Himmel, H.(1927): Gips von Wiesloch(Baden). Centralblatt für Mineralogie, Abt. A (1927), 342-349)

Activator(s) and spectrum:

Activator(s): ST (Singlet-triplet)-Matière organique en impureté, (UO₂)²⁺ (ion Uranyle) en impureté,  

Peaks in the spectrum (nm):

ST  : 440-630nm 

494nm, 510nm, 544nm, 601nm (Hourglass figure, Canada)

 UO₂²⁺ : 469, 486, 507, 530, 554nm (sample from Morrocco)

Col. G.Barmarin; Photo: G. Barmarin

Spectrum Galery:

  
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Comments on spectrum and activators:

Typical uranyl spectrum when green luminescence is present.
Greenish-white and bluish fluorescence most probably due to organic impurities.

Best localities for fluorescence (*):

• Hourglass figure: Willow creek, Nanton, Alberta, Canada;
• Alabaster Quarries, Patillas Hill, Fuentes de Ebro, Delimitación Comarcal de Zaragoza, Zaragoza, Aragon  Spain (2004);
• Red River Floodway, Winnipeg, Manitoba, Canada ;
• Guerrero Negro, Mun. de Mulegé, Baja California Sur, Mexico (zoned blue+orange-pink LW);
• Camp Verde, Camp Verde District, Yavapai Co., Arizona, USA (pseudomorph after glauberite);
• Salinas de Otuma, Otuma village, Paracas, Pisco, Pisco Province, Ica Department, Peru;
• Dämmelwald clay pit, Wiesloch, Baden-Württemberg, Germany

(*)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 ,

Reference for luminescence on the Internet:

Mineralogical reference on the Internet:

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

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

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