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Improved powder X-ray data for cancrinites I: Afghanite

Published online by Cambridge University Press:  10 January 2013

Paolo Ballirano
Affiliation:
Dipartimento di Scienze della Terra, Università degli Studi di Roma “La Sapienza,” P.le Aldo Moro, 5, Roma, I-00185, Italy
Adriana Maras
Affiliation:
Dipartimento di Scienze della Terra, Università degli Studi di Roma “La Sapienza,” P.le Aldo Moro, 5, Roma, I-00185, Italy
Peter R. Buseck
Affiliation:
Departments of Geology and Chemistry, Arizona State University, Tempe, Arizona 85287-1404, USA
Su Wang
Affiliation:
Departments of Geology and Chemistry, Arizona State University, Tempe, Arizona 85287-1404, USA
Ann M. Yates
Affiliation:
Departments of Geology and Chemistry, Arizona State University, Tempe, Arizona 85287-1404, USA

Abstract

Afghanite is a feldspathoid of the cancrinite-group: It is hexagonal, space group P63mc. The afghanite sample was found in the M. Somma-Vesuvio volcanic complex (Italy) and was previously described as davyne: Calculated cell parameters are a = 12.7997(4) Å, c = 21.4062(11) Å; the volume is 3037.2(2) Å3. The strongest lines are: 3.694(100), 3.647(56), 4.826(30), 2.678(25), 2.134(18), 3.999(12), 2.750(12), and 2.771(10). The new data provide quantitative measurement of intensities, an increased number of indexed peaks, and a different empirical formula with respect to the PDF 20-1086.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

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