phillipsite and offretite-erionite from limburgite amygdules. Faujasite ... K e y w o r d s : Crystal chemistry, zeolite, erionite, faujasite, offretite, phillipsite, chemical ...
N . Jb. Miner. Mh.
Jg. 1975, H . 10
433-443
Stuttgart, Oktober 1975
Chemistry and paragenesis of faujasite, phillipsite and offretite f r o m Sasbach, Kaiserstuhl, Germany By Romano Rinaldi and J. V. Smith, Chicago, Ilhnois, U.S. A., and Gerhard Jung, Albbruck, Germany
With 3 figures and 4 tables in the text
R I N A L D I , R . , SMITH, J. V . & JUNG, G . : Chemistry and paragenesis of faujasite,
phillipsite and offretite from Sasbach, Kaiserstuhl, Germany. - N . Jb. Miner. Mh., 1975, H . 10, 433-443, Stuttgart 1975. Abstract: Electron microprobe analyses show composition variation in faujasite, phillipsite and offretite-erionite from limburgite amygdules. Faujasite has 52-60 A l , 8-15 Mg, 4-15 Ca, 7-15 Na and 1-10 K atoms per 384 oxygens: each crystal is uniform, but there is no explanation of the between-crystal variability. Often clear octahedra are coated by amorphous, hydrated silica-alumina, as are augite crystals and cavities free of faujasite. Phillipsite occurs as radiai twinned aggregates, and as twinned individuals up to 1 mm long. The radiai aggregates often grow around and on faujasite octahedra, sometimes as small spherules. Mg and Ca decrease and Na increases in large phillipsite crystals projecting into a cavity (Mg 0.14^0.03; Ca 1 . 2 ^ 0 . 9 ; Na 0.5-> 0.8; atoms per 32 oxygens). One sample contained offretite-erionite barrels i n the same amygdules as phillipsite, faujasite and coating. The crystallization sequence is faujasite (and offretite), coating, phillipsite, and calcite, but not ali amygdules show the complete sequence. No evidence was seen for breakdown of faujasite. K e y w o r d s : Crystal chemistry, zeolite, erionite, faujasite, offretite, phillipsite, chemical analysis, interpretation; Upper Rhine Valley (NW-Kaiserstuhl, Sasbach Quarry).
Introduction
Sasbach, Kaiserstuhl, Germany has been known since 1842 as the principal locality for the occurrence of faujasite (see H I N T Z E , 1893). Specimens
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Chcmistry and paragenesis of faujasite
R. Rinaldi, J. V . Smith and G . Jung
f r o m Annerod and Grofien Buseck i n Hessen, Germany have not been studied b y modem techniques, but electron microprobe and X - r a y studies are n o w i n progress. The only other verified locality is Oahu, H a w a i i ( I i j i M A & H A R A D A , 1969). Because of the great commercial importance of the synthetic analogs, Linde Y and X , as molecular sieve catalysts (BRECK, 1974), we studied the paragenesis of Sasbach samples. Most specimens were collected b y G. J U N G i n 1967 and by J U N G and J. V . S M I T H i n 1969
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