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Acmonidesite, a new ammonium sulfate chloride from La Fossa crater, Vulcano, Aeolian Islands, Italy

Published online by Cambridge University Press:  29 May 2018

Francesco Demartin*
Affiliation:
Università degli Studi di Milano, Dipartimento di Chimica, via Golgi 19, I-20133 Milano, Italy
Carlo Castellano
Affiliation:
Università degli Studi di Milano, Dipartimento di Chimica, via Golgi 19, I-20133 Milano, Italy
Italo Campostrini
Affiliation:
Università degli Studi di Milano, Dipartimento di Chimica, via Golgi 19, I-20133 Milano, Italy
*
Author for correspondence: Francesco Demartin, Email: francesco.demartin@unimi.it

Abstract

The new mineral acmonidesite, (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8, was found in an active fumarole (fumarole FA, temperature ~250°C) at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as brown prismatic crystals up to 0.10 mm long, in association with salammoniac, alunite and adranosite. The mineral is orthorhombic, space group C2221 (no. 20) with a = 9.841(1), b = 19.448(3) c = 17.847(3) Å, V = 3415.7(9) Å3 and Z = 4. The six strongest reflections in the powder X-ray diffraction pattern are: [dobs in Å(I)(hkl)] 8.766(100)(110), 1.805(88)(390), 5.178(45)(131), 4.250(42)(221), 2.926(42)(330) and 2.684(32)(261). The empirical formula (based on 28 anions per formula unit [pfu]) is (NH4)5.77K1.42Pb0.62Na1.24Fe3.96Mn0.08S5.04O20.16Cl7.97Br0.08. The idealised formula is (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8. The calculated density is 2.551 g cm–3. Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.0363 for 4614 independent observed reflections [I > 2σ(I)]. The structure contains two independent, distorted octahedral iron sites, Fe1 and Fe2, with the iron atoms in the 2+ oxidation state, as confirmed by the interatomic distances and bond-valence calculations (2.06 and 1.94 vu, respectively). Fe1 is surrounded by two chlorine atoms and four oxygens of the sulfate ions, with the following average distances (Å): Fe1–O 2.125 and Fe1–Cl 2.472; and Fe2 is surrounded by three chlorine atoms and three oxygens of the sulfate ions, with the following average distances (Å): Fe2–O 2.110 and Fe2–Cl 2.531. Three independent sulfate anions are also present and are connected with the iron polyhedra to form a three-dimensional structure containing voids occupied by four independent ammonium ions (two of them partially replaced by K+), one Na+/Pb2+ site and one Cl ion.

Type
Article
Copyright
Copyright © Mineralogical Society of Great Britain and Ireland 2018 

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Footnotes

Associate Editor: Giancarlo Della Ventura

References

Borodaev, Y.S., Garavelli, A., Garbarini, C., Grillo, S.M., Mozgova, N.N., Organova, N.I., Trubkin, N.V. and Vurro, F. (2000) Rare sulfosalts from Vulcano, Aeolian Islands, Italy. III. Wittite and cannizzarite. The Canadian Mineralogist, 38, 2334.Google Scholar
Brown, I.D. (2009) Recent developments in the methods and applications of the bond valence model. Chemical Reviews, 109, 68586919.Google Scholar
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244247.Google Scholar
Campostrini, I., Demartin, F., Gramaccioli, C.M. and Russo, M. (2011) Vulcano. Tre secoli di mineralogia. Associazione Micro-mineralogica Italiana (editors), Cremona, Italy, 344 pp, ISBN 978-88-905541-0-0.Google Scholar
Demartin, F., Gramaccioli, C.M. and Campostrini, I. (2010) Adranosite, (NH4)4NaAl2(SO4)4Cl(OH)2, a new ammonium sulfate chloride from La Fossa Crater, Vulcano, Aeolian Islands, Italy. The Canadian Mineralogist, 48, 315321.Google Scholar
Demartin, F., Campostrini, I. and Castellano, C. (2013) Acmonidesite, IMA 2013-068. CNMNC Newsletter No. 18, December 2013, page 3250; Mineralogical Magazine, 77, 32493258.Google Scholar
Demartin, F., Castellano, C. and Campostrini, I. (2014) Therasiaite, (NH4)3KNa2Fe2+Fe3+(SO4)3Cl5, a new sulfate chloride from La Fossa Crater, Vulcano, Aeolian Islands, Italy. Mineralogical Magazine, 78, 203213.Google Scholar
Farrugia, L.J. (1999) WinGX suite for small-molecule single-crystal crystallography. Journal of Applied Crystallography, 32, 837838.Google Scholar
Fischer, R.X. and Tillmanns, E. (1988) The equivalent isotropic displacement factor. Acta Crystallographica, C44, 775776.Google Scholar
Hawthorne, F.C., Krivovichev, S.V. and Burns, P.C. (2000) The crystal chemistry of sulfate minerals. Pp. 1112 in: Sulfate Minerals – Crystallography, Geochemistry, and Environmental Significance (Alpers, C.N., Jambor, J.L. and Nordstrom, B.K., editors). Reviews in Mineralogy and Geochemistry, 40. Mineralogical Society of America and the Geochemical Society, Washington DC.Google Scholar
Holland, T.J.B. and Redfern, S.A.T. (1997) Unit cell refinement from powder diffraction data: the use of regression diagnostics. Mineralogical Magazine, 61, 6577.Google Scholar
Mandarino, J.A. (1976) The Gladstone-Dale relationship I. Derivation of new constants. The Canadian Mineralogist, 14, 498502.Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship. IV. The compatibility index and its application. The Canadian Mineralogist, 19, 441450.Google Scholar
Mitolo, D., Demartin, F., Garavelli, A., Campostrini, I., Pinto, D., Gramaccioli, C.M., Acquafredda, P. and Kolitsch, U. (2013) Adranosite-(Fe), (NH4)4NaFe2(SO4)4Cl(OH)2, a new ammonium chloride from La Fossa Crater, Vulcano, Aeolian Islands, Italy. The Canadian Mineralogist, 51, 5766.Google Scholar
Pinto, D., Balić Žunić, T., Garavelli, A., Garbarino, C., Makovický, E. and Vurro, F. (2006) First occurrence of close-to-ideal kirkiite at Vulcano (Aeolian Islands, Italy): chemical data and single crystal X-ray study. European Journal of Mineralogy, 18, 393401.Google Scholar
Plášil, J., Petřiček, V and Majzlan, J. (2017) A commensurately modulated structure of parabutlerite, FeIIISO4(OH)·2H2O. Acta Crystallographica, B73, 856862.Google Scholar
Sheldrick, G.M. (2000) SADABS Area-Detector Absorption Correction Program, Bruker AXS Inc., Madison, WI, USA.Google Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112122.Google Scholar
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