Mineralogical characterization of paulingite from Vinarická Hora, Czech Republic
- Autor(en)
- Christian Lengauer, Gerald Giester, Ekkehart Tillmanns
- Abstrakt
A sample of the zeolite paulingite from the locality Vinaricka Hora, Czech Republic, was investigated by means of chem., thermal, powder and single crystal x-ray methods. The fully transparent, colorless to pale yellow crystals exhibit the form {110} and occur together with phillipsite. The chem. compn. is (Ca2.57K2.28Ba1.39Na0.38)(Al11.55Si30.59O84)×27H2O, Z = 16 with minor amts. of Mg (<0.05), Sr (<0.13), Mn (<0.01), and Fe (<0.04). The chem. differences from previously described paulingites are a high Ba-content, a lower Si/(Al+Fe) ratio of 2.64, and a reduced water-content. The calcd. d. is 2.098 g cm-3, and the obsd. refractive index is 1.482(2). The dehydration behavior is characterized by a main wt. loss from 24-190°C (-11.2 wt.%, .simeq.21H2O) and a minor wt. loss from 190-390°C (-3.1 wt.%, .simeq. 6H2O). The rehydration capability was proven up to 150°C. The dehydration process during the main wt. loss is accompanied by a redn. of the cell vol. of 11%. The refined lattice parameters of the x-ray powder data are a = 35.1231(5).ANG. and a = 33.7485(8).ANG. of an untreated and a dehydrated sample, resp. A breakdown of the paulingite structure can be obsd. while the remaining water content decomps. The single crystal x-ray refinement of this chem. different sample material derived three main cation positions, which are inside a so called paulingite or pi-cage (Ca), between 8-rings of neighboring pi-cages (Ba), and in the center of the non-planar 8-rings of the gamma-cage (K). Further partially occupied cation positions (Ca,Na) were located in the planar 8-rings of the alpha- and gamma-cages. No positions within the double 8-membered rings were detected. The water is localized around the main cation positions and in three clusters of partially occupied sites.
- Organisation(en)
- Institut für Mineralogie und Kristallographie
- Journal
- Mineralogical Magazine
- Band
- 61
- Seiten
- 591-606
- Anzahl der Seiten
- 16
- ISSN
- 0026-461X
- DOI
- https://doi.org/10.1180/minmag.1997.061.407.10
- Publikationsdatum
- 08-1997
- Peer-reviewed
- Ja
- ÖFOS 2012
- 105113 Kristallographie, 105116 Mineralogie
- Schlagwörter
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/mineralogical-characterization-of-paulingite-from-vinarick-hora-czech-republic(dde7a56b-5dc4-4080-8b68-80dba4aa035a).html