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Titel |
Fluorescent halite from Bochnia salt mine, Poland |
VerfasserIn |
Edyta Waluś, Dobrochna Głąbińska, Aleksandra Puławska, Michał Flasza, Maciej Manecki |
Konferenz |
EGU General Assembly 2016
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Medientyp |
Artikel
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Sprache |
en
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 18 (2016) |
Datensatznummer |
250128510
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Publikation (Nr.) |
EGU/EGU2016-8505.pdf |
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Zusammenfassung |
The photoluminescence of selected halite crystals from Bochnia Salt Mine (Bochnia, Poland)
were discovered in 2014. This is a result of contemporary precipitation from percolating
waters. In most cases the fluorescence is observed in whole crystals or in zones of crystals.
Only clear parts of transparent crystals are orange-red fluorescent in short UV light (320 nm).
Chemical microanalysis by scanning electron microscopy/energy dispersive spectroscopy
SEM/EDS indicates that this is activated by Mn and Pb. The concentration of Mn is similar in
fluorescent and inactive salt and equals to 0.13 – 0.27 wt.%. The concentration of Pb,
however, averages to 3.8 wt.% in fluorescent parts reaching only 1.9 wt.% elsewhere. There is
no difference in the unit cell parameters determined by powder X-ray diffraction. The
percolating waters contain some Mn (ca. 3.9 ppm) but the concentration of Pb is below the
detection limits.
The experiments of precipitation of halite from the solutions containing various
concentrations of Mn and Pb were performed to simulate this fenomenon using
solutions containing: 1 mg Pb/L and 80 mg Mn/L; 1 mg Pb/L and 0.8 mg Mn/L; 1 mg
Pb/L and 0.6 mg Mn/L; and 0 mg Pb/L and 80 mg Mn/L. The results indicate that
fluorescence is apparent when halite forms from solutions containing more than
0.8 mg Mn/L and more than 1 mg Pb/L. The presence of lead as co-activator is
necessary requirement: Mn alone does not activate the fluorescence of halite. This is in
accordance with the results of previous work (Murata et al., 1946; Sidike et al.,
2002).
Rock salt in the mine does not show fluorescence at all. Fluorescence of contemporary
salt in Bochnia salt mine is a result of mining activity and slight, sporadic contamination
with traces of Mn and Pb. This work is partially funded by AGH research grant no
11.11.140.319.
Murata K. J., Smith R. L., 1946. Manganese and lead as coactivators of red fluorescence
in halite, American Mineralogist, Volume 31, pages 527-538
Sidike A., Kausachi I., Yamashita N., 2002. Energy transfer from Pb2+ to Mn2+ in
fluorescent halite from Salton Sea, California, Journal of Mineralogical and Petrological
Sciences, Volume 97, page 278-284 |
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