Hostname: page-component-76fb5796d-wq484 Total loading time: 0 Render date: 2024-04-27T21:05:54.963Z Has data issue: false hasContentIssue false

Naalasite, NaAl(AsO3OH)2⋅H2O, the Al analogue of nafeasite from the Torrecillas mine, Iquique Province, Chile

Published online by Cambridge University Press:  22 January 2024

Anthony R. Kampf*
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA
Gerhard Möhn
Affiliation:
Independent Researcher, Dr.-J.-Wittemannstrasse 5, 65527 Niedernhausen, Germany
Chi Ma
Affiliation:
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
Joy Désor
Affiliation:
Independent Researcher, Bad Homburg, Germany
*
Corresponding author: Anthony R. Kampf; Email: akampf@nhm.org

Abstract

The new mineral naalasite (IMA2023–027), NaAl(AsO3OH)2⋅H2O, was found at the Torrecillas mine, Iquique Province, Chile, where it is a secondary alteration phase associated with anhydrite, juansilvaite, magnesiokoritnigite and a lavendulan-like phase. Naalasite occurs in tightly intergrown aggregates and druses of equant crystals. Crystals are light to medium pink and transparent, with vitreous lustre and white streak. The Mohs hardness is ~3½. The density is 3.19(2) g⋅cm–3. Optically, naalasite is uniaxial (+), with ω = 1.630(3) and ɛ = 1.660(3) (white light). The empirical formula (based on 9 O apfu) is Na0.92Al0.61Fe3+0.39As2O9H4.07. Naalasite is trigonal, space group R32, with cell parameters: a = 8.494(4), c = 26.430(13) Å, V = 1651.5(4) Å3 and Z = 9. The structure, refined to R1 = 3.78% for 641 I > 2σI reflections, is based on a loose 3D framework of alternating AsO3OH tetrahedra and AlO6 octahedra. The structure is topologically equivalent to that of nafeasite and can be regarded as its Al analogue, even though nafeasite is monoclinic with space group C2.

Type
Article
Copyright
Copyright © The Author(s), 2024. Published by Cambridge University Press on behalf of The Mineralogical Society of the United Kingdom and Ireland

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.)

Footnotes

Associate Editor: Charles A Geiger

References

Buchelt, M. and Tellez, C. (1988) The Jurassic La Negra Formation in the area of Antofagasta, north Chile (lithology, petrography, geochemistry). Pp 171182 in: The Southern Central Andes (Bahlburg, H, Breitkreuz, C and Giese, P, editors). Lecture Notes in Earth Sciences 17, Springer, Berlin Heidelberg New York.Google Scholar
Cameron, E.M., Leybourne, M.I. and Palacios, C. (2007) Atacamite in the oxide zone of copper deposits in northern Chile: involvement of deep formation waters? Mineralium Deposita, 42, 205218.10.1007/s00126-006-0108-0CrossRefGoogle Scholar
Donnay, J.D.H. and Harker, D. (1937) A new law of crystal morphology extending the Law of Bravais. American Mineralogist, 22, 446467.Google Scholar
Ferraris, G. and Ivaldi, G. (1988) Bond valence vs. bond length in O⋯O hydrogen bonds. Acta Crystallographica, B44, 341344.10.1107/S0108768188001648CrossRefGoogle Scholar
Gagné, O.C. and Hawthorne, F.C. (2015) Comprehensive derivation of bond-valence parameters for ion pairs involving oxygen. Acta Crystallographica, B71, 562578.Google ScholarPubMed
García, F. (1967) Geologia del Norte Grande de Chile. Simposio Geosinclinal Andino, Sociedad Geológica de Chile Publicaciones, 3, 138 pp.Google Scholar
Gutiérrez, H. (1975) Informe sobre una rápida visita a la mina de arsénico nativo, Torrecillas. Instituto de Investigaciones Geológicas, Iquique, Chilie.Google Scholar
Higashi, T. (2001) ABSCOR. Rigaku Corporation, Tokyo.Google Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2019) Camanchacaite, chinchorroite, espadaite, magnesiofluckite, picaite and ríosecoite: six new hydrogen-arsenate minerals from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 83, 655671.10.1180/mgm.2019.28CrossRefGoogle Scholar
Kampf, A.R., Schluter, J., Malcherek, T., Paulenz, B., Pohl, D., Ma, C., Dini, M. and Molina Donoso, A.A. (2022) Nafeasite, Na3Fe3+3(AsO3OH)6⋅3H2O, a new framework arsenate from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 86, 883890.10.1180/mgm.2022.58CrossRefGoogle Scholar
Kampf, A.R., Möhn, G., Ma, C. and Désor, J. (2023) Naalasite, IMA 2023-027. CNMNC Newsletter 74; Mineralogical Magazine, 87, https://doi.org/10.1180/mgm.2023.54Google Scholar
Majzlan, J., Drahota, P. and Filippi, M. (2014) Parageneses and crystal chemistry of arsenic minerals. Pp. 17184 in: Arsenic – Environmental Geochemistry, Mineralogy, and Microbiology (Bowell, Robert J., Alpers, Charles N., Jamieson, Heather E., Kirk Nordstrom, D. and Majzlan, Juraj, editors). Reviews in Mineralogy and Geochemistry, 79. Mineralogical Society of America and the Geochemical Society, Chantilly, Virginia, USA.10.1515/9781614517979.17CrossRefGoogle Scholar
Mandarino, J.A. (2007) The Gladstone–Dale compatibility of minerals and its use in selecting mineral species for further study. The Canadian Mineralogist, 45, 13071324.10.2113/gscanmin.45.5.1307CrossRefGoogle Scholar
Schwendtner, K. and Kolitsch, U. (2018) M +M 3+2As(HAsO4)6 and α-and β-M +M 3+(HAsO4)2 (M +M 3+ = RbAl or CsFe): six new compounds crystallizing in three closely related structure types. Acta Crystallographica, C74, 721727.Google Scholar
Sheldrick, G.M. (2015a) SHELXT – Integrated space-group and crystal-structure determination. Acta Crystallographica, A71, 38.Google ScholarPubMed
Sheldrick, G.M. (2015b) Crystal Structure refinement with SHELX. Acta Crystallographica, C71, 38.Google Scholar
Supplementary material: File

Kampf et al. supplementary material 1

Kampf et al. supplementary material
Download Kampf et al. supplementary material 1(File)
File 126.8 KB
Supplementary material: File

Kampf et al. supplementary material 2

Kampf et al. supplementary material
Download Kampf et al. supplementary material 2(File)
File 106.3 KB
Supplementary material: File

Kampf et al. supplementary material 3

Kampf et al. supplementary material
Download Kampf et al. supplementary material 3(File)
File 25.3 KB