Three ammonium-iron-sulfite phases from a burning dump of the Vasas abandoned opencast coal mine (Pécs, Mecsek Mountains, Hungary) and the new mineral kollerite
- Autor(en)
- Béla Fehér, Sándor Szakáll, Martin Ende, Herta S. Effenberger, Judith Mihály, István Sajó, László Kótai, Dávid Szabó
- Abstrakt
Three ammonium-iron-sulfites (AIS) from a burning coal dump in an abandoned open coal pit at Pécs-Vasas (Mecsek Mountains, South Hungary) were identified: (NH4)9Fe3+(SO3)6 (AIS-1), (NH4)2Fe2+(SO3)2 (AIS-2), and (NH4)2Fe3+(OH)(SO3)2·H2O (AIS-3). They were formed by the interaction of decomposing iron sulfides and ammonia released from organic matter. AIS-1 and AIS-2 are metastable; they break down in a few weeks (AIS-1) respectively years (AIS-2). AIS-1 forms red, stubby columnar to thick tabular crystals up to 0.2 mm in length. AIS-2 appears as brown tabular to short prismatic crystals up to 0.1 mm, often they create columnar intergrowths. AIS-3 is more stable. It was approved as a new mineral species (mineral name kollerite, IMA-CNMNC 2018–131). Sprays of natural kollerite up to 1.5 mm are composed of yellow, long-prismatic or lath-like crystals up to 0.1 mm in length. AIS-1 is characterized by powder-X-ray diffraction only. The crystal structures of AIS-2 [synthetic material, R¯3m, a = 5.3879(8), c = 19.980(4) Å] and kollerite [Cmcm, a = 17.803(15), b = 7.395(5), c = 7.096(5) Å] were investigated by single-crystal X-ray diffraction. AIS-2 is topologically equivalent to bütschliite. Isolated Fe2+O6 polyhedra are corner-connected to sulfite anions. 2D nets with composition [Fe2+(SO3)2]2− are parallel to (0001). Kollerite crystallizes in a new structure type. The FeO6 octahedra are corner linked to buckled [Fe3+(OH)(SO3)2]2− chains. In both cases, ammonium cations are intercalated. Connection is verified by hydrogen bonds only; all H atom positions are located experimentally.
- Organisation(en)
- Institut für Mineralogie und Kristallographie
- Externe Organisation(en)
- Herman Ottó Museum, University of Miskolc, Research Centre for Natural Sciences, University of Pécs, Eötvös Loránd University Budapest
- Journal
- Mineralogy and Petrology
- Band
- 117
- Seiten
- 231-245
- Anzahl der Seiten
- 15
- ISSN
- 0930-0708
- DOI
- https://doi.org/10.1007/s00710-023-00818-1
- Publikationsdatum
- 05-2023
- Peer-reviewed
- Ja
- ÖFOS 2012
- 105116 Mineralogie, 105113 Kristallographie
- Schlagwörter
- ASJC Scopus Sachgebiete
- Geophysics, Geochemistry and Petrology
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/7124036e-e7f3-421e-bf03-84f71b191e8b