Synchrotron X-ray Rietveld study of perlialite, the natural counterpart of synthetic zeolite-L
Artioli, Gilberto; Kvick, Åke
European Journal of Mineralogy Volume 2 Number 6 (1990), p. 749 - 760
published: Dec 19, 1990
manuscript accepted: Jun 6, 1990
manuscript received: Feb 7, 1990
ArtNo. ESP147050206002, Price: 29.00 €
Abstract The crystal structure of perlialite from the Murun Massif, U.S.S.R. was determined and refined using synchrotron X-ray powder data. The framework type of this natural zeolite is the same as synthetic zeolite Linde-L. Extraframework cation and water oxygen position were located, and the locations and occupancies show large differences with respect to the cation and water sites previously reported for the synthetic zeolites K-L and Ba, K-L. Refinement results and subsequent chemical analysis on the Murun sample lead us to revise the unit cell formula of perlialite to: K8Tl4AI12Si24O72 ⋅ 20H2O. The chemical formula has a Tl content not shown in the original chemical analyses of the species. Space group P 6/m mm was confirmed and the refined cell parameters are a = 18.5432(4), c = 7.5310(3) Å. A Rietveld refinement of the same sample using conventional automated powder diffractometer data confirmed the structural model and crystallochemical details.