The Crystal Structure of Kogarkoite, Na3SO4F

L. Fanfani, G. Giuseppetti, C. Tadini and P. F. Zanazzi
Istituto di Mineralogia, Università di Cagliari, Italy
Istituto di Mineralogia, Università di Pavia, Italy
Istituto di Mineralogia, Università di Perugia, Italy

Summary: The crystal structure of synthetic kogarkoite has been determined from X-ray data collected on an automatic diffractometer. The refinement was performed by a least-squares method employing anisotropic thermal parameters. The 3157 reflections with I > 3σ(I) converged to a conventional R value of 0.033. The cell content is 12 Na3SO4F, the space-group P21/m, a = 18.074, b = 6.958, c = 11.443 Å, β = 107.71°.

Kogarkoite presents a marked trigonal subcell with c′ corresponding to [102] of the monoclinic cell. The tridimensional framework can be considered built up by nine differently stacked layers of Na atoms approximately perpendicular to the c′ axis (five sheets are present in galeite, six in sulphohalite, and seven in schairerite). The very close structural relationships between these minerals are discussed.

Mineralogical Magazine; June 1980 v. 43; no. 330; p. 753-759; DOI: 10.1180/minmag.1980.043.330.08
© 1980, The Mineralogical Society
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