Hostname: page-component-848d4c4894-r5zm4 Total loading time: 0 Render date: 2024-06-27T14:20:01.153Z Has data issue: false hasContentIssue false

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Appleman, D. E., and Evans, H. T. Jr., (1973). “Indexing and leastsquares refinement of powder diffraction data,” U.S. Nat. Tech. Inf. Serv. Doc. PB216188.Google Scholar
Bariand, P., Cesbron, F., and Giraud, R. (1968). “Une nouvelle espece minerale: l'afghanite de Sar-e-Sang, Badakhshan, Afghanistan. Comparison avec les mineraux du groupe de la cancrinite,” Bull. Soc. fr. Minéral. Cristallogr. 91, 3442.Google Scholar
Benoit, P. H. (1987). “Adaptation to microcomputer of the Appleman–Evans program for indexing and least-squares refinement of powder-diffraction data for unit-cell dimensions,” Am. Miner. 72, 10181019.Google Scholar
Hogarth, D. D. (1979) “Afghanite: new occurrences and chemical composition,” Can. Miner. 17, 4752.Google Scholar
Ivanov, V. G., and Sapozhnikov, A. N. (1975). “The first find of afghanite in the U.S.S.R.,” Zap. Vses. Mineral. Obshchest. 104, 328331 (in Russian).Google Scholar
Leoni, L., Mellini, M., Merlino, S., and Orlandi, P. (1979). “Cancrinite-like minerals: new data and crystal chemical considerations,” Rend. S.I.M.P. 35 (2), 713719.Google Scholar
Merlino, S., and Mellini, M. (1976). “Crystal structures of cancrinite-like minerals,” Zeolite '76. Program and Abstracts, Tucson, AZ, 47.Google Scholar
Parodi, G. C. (1982). “Infrared spectroscopy of minerals: the cancrinitegroup,” Tesi di laurea in Scienze Geologiche (not published), Università degli Studi di Roma “La Sapienza” (in Italian).Google Scholar
Pobedimskaya, E. A., Rastsvetaeva, R. K., Terentieva, L. E., and Sapozhnikov, A. N. (1991). “Crystal structure of afghanite,” Dokl. Akad. Nauk S.S.S.R. 320, 882886 (in Russian).Google Scholar
Smith, G. S., and Snyder, R. L. (1979). “FN: A criterion for rating powder diffraction patterns and evaluating the reliability of powder-pattern indexing,” J. Appl. Cryst. 12, 60.CrossRefGoogle Scholar
Wolff de, P. M. (1968). “A simplified criterion for the reliability of a powder pattern indexing,” J. Appl. Cryst. 1, 108.CrossRefGoogle Scholar