GYPSUM
Chemical Formula: CaSO4 2H2O
Familly: Sulfates
Status: IMA-GP
Crystal System: Monoclinic
Mineral for Display: Yes
Associated names (luminescent varieties, discredited names, synonymes etc.):
alabaster, selenite,
Luminescence:
UV Type |
Main color |
Intensity |
Observation Frequency |
|
| | | |
Long Waves (365nm): | Yellowish White | Medium | Often | Short Waves (254 nm): | Bluish White | Medium | Often | | | | |
Other colors LW: | White , Bluish White , Pale Yellow , Orangy yellow , Greenish , Greenish white , Yellowish , |
Other colors SW: | White , Bluish White , Yellowish White , Pinkish White , Pale Yellow , Yellowish Green , Greenish , Greenish white , Yellowish , |
Long Waves Picture (365nm)
OL (365 nm). Col. G. Barmarin; Photo: G. Barmarin
Short Waves Pictures (254nm)
OC (254 nm). Col. G. Barmarin; Photo: G. Barmarin
Galerie de photos:
...
To the gallery (15 images in the gallery)
Phosphorescence (in the common meaning of the term) seen by naked eye:
UV Type |
Color |
Intensity |
Observation Frequency |
Long Wave (365nm): | Yellowish White | Strong | |
Short Waves (254 nm): | Bluish White | Strong | |
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)
Main Activator(s) and spectrum:
Most Common Activator: Organic impurities
Other activators: (UO2)2+ (Uranyl ion) as impurities ,
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
...
To the spectrum gallery (2 spectra in the gallery)
Comments on activators and spectra:
Typical uranyl spectrum when green luminescence is present.
Greenish-white and bluish fluorescence most probably due to organic impurities.
Best Locality for luminescence(*):
- 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
(*)Data are not exhaustive and are limited to the most important localities for fluorescence
Bibliographical 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 ,
Luminescence Reference on internet:
- Iwase, Ei-ichi (1936): Über die Verteilung des Lumineszenzträgers im Gipskristall. Bulletin of the Chemical Society of Japan 11, 475-479
- https://www.researchgate.net/publication/235924582_Photoluminescence_properties_of_gypsum
- Fluorescerende gips van Saragossa, Geonieuws (MKA) November 2009
- Fluorescerende gips van Betekom, Vlaams-Brabant, Geonieuws (MKA), Augustus 2013
- MONT-SAINT-HILAIRE, History, Geology, Mineralogy, Laszlo HORVATH, The Canadian Mineralogist, Special Publication 14, 2019
Image(s):
Mineralogical Reference on internet:
http://www.mindat.org/show.php?name=Gypsum
http://webmineral.com/data/Gypsum.shtml
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