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Saccoite, Ca2Mn+32F(OH)8⋅0.5(SO4), a new, microporous mineral from the Kalahari Manganese Field, South Africa

Published online by Cambridge University Press:  13 July 2022

Gerald Giester Open the ORCID record for Gerald Giester [Opens in a new window] ,
Christian L. Lengauer ,
Chutimun Chanmuang N. ,
Dan Topa ,
Jens Gutzmer  and
Karl-Ludwig von Bezing
Gerald Giester*
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien - Geozentrum, Josef-Holaubek-Platz 2, 1090 Wien, Austria
Christian L. Lengauer
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien - Geozentrum, Josef-Holaubek-Platz 2, 1090 Wien, Austria
Chutimun Chanmuang N.
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien - Geozentrum, Josef-Holaubek-Platz 2, 1090 Wien, Austria
Dan Topa
Affiliation:
Naturhistorisches Museum Wien, Burgring 7, 1010 Vienna, Austria
Jens Gutzmer
Affiliation:
Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Chemnitzer Str. 40, 09599 Freiberg, Germany
Karl-Ludwig von Bezing
Affiliation:
Independent Researcher, Kimberley 8301, RSA
*
*Author for correspondence: Gerald Giester, Email: gerald.giester@univie.ac.at
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Abstract

Saccoite, Ca2Mn3+2F(OH)8⋅0.5(SO4), is a new mineral found at the N'Chwaning III mine, Kalahari Manganese Field, Northern Cape Province, Republic of South Africa. It occurs as fillings of voids in hydrothermally altered manganese ore (comprising mostly of bixbyite and baryte). Further associated minor minerals are braunite, gypsum, chlorite, sturmanite and ettringite. Saccoite forms small needles, felted crystal masses or crusts. The new mineral is olive green, transparent, with white streak and vitreous lustre. No luminescence is observed. Saccoite is uniaxial (–) with refractive indices at 589(1) nm of ω = 1.705(5) and ɛ = 1.684(2). Pleochroism is distinct, i.e. bluish green (ω) and yellowish green (ɛ). The chemical composition was studied by means of an electron probe micro-analyser (EPMA) using wavelength-dispersive X-ray spectrometry (WDS). The empirical mineral formula is Ca2.06Mn3+1.78Cu0.10Mg0.07F0.97(OH)8.02(SO4)0.39. The unit-cell dimensions of saccoite (space group P4/ncc) are a = 12.834(3) Å, c = 5.622(2) Å, V = 926.0(4) Å3), and the calculated mass density is 2.73 g⋅cm–3. Saccoite exhibits a heteropolyhedral framework structure that is composed of edge- and corner sharing CaF2(OH)6 and M(OH)6 polyhedra (M = Mn3+ and Cu2+) with large channels along [001], which host disordered and only partially occupied groups, especially SO42–. The hydrogen atoms of the OH groups point into the channel to form hydrogen bonds with the channel anions. Ca–F distances are ~2.3 Å, the Ca–OH distances in the range of 2.44–2.58 Ǻ, and the M(OH)6 octahedron is strongly 4+2 Jahn-Teller distorted (4 × ~1.92 Å, 2 × 2.27 Å). The F atom is tetrahedrally coordinated to calcium atoms. The strongest lines in the powder X-ray diffraction pattern [d in Å (relative intensity) (hkl)] are: 9.0735 (35) (110), 4.5370 (95) (220), 4.0644 (20) (310), 3.0105 (100) (321), 2.8117 (20) (002), 2.7242 (75) (411), 1.9755 (35) (611), and 1.8142 (20) (550).

Keywords

saccoiteCa2Mn+32F(OH)8⋅0.5(SO4)new mineralmicroporous structureKalahari Manganese FieldSouth Africa
Type
Article
Information
Mineralogical Magazine , Volume 86 , Issue 5 , October 2022 , pp. 814 - 820
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of The Mineralogical Society of Great Britain and Ireland

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Footnotes

Associate Editor: Sergey V Krivovichev

References

Brese, N.E. and O'Keeffe, M. (1991) Bond-valence Parameters for Solids. Acta Crystallographica, B47, 192–197.CrossRefGoogle Scholar
Bruker, (2020) APEX3. Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Cairncross, B., Beukes, N.J. and Gutzmer, J. (1997) The Manganese Adventure: The South African Manganese Fields. Associated Ore & Metal Corporation Limited, South Africa.Google Scholar
Dowty, E. (2016) ATOMS (Version 6.5.0). Shape Software, Kingsport, Tennessee, USA.Google Scholar
Foster, M.D., Rivin, I., Treacy, M.M.J. and Delgado Friedrichs, O. (2006) A geometric solution to the largest-free-sphere problem in zeolite frameworks. Miocroporous and Mesoporous Materials, 90, 32–38.CrossRefGoogle Scholar
Giester, G. and Rieck, B. (1994) Effenbergerite, BaCu[Si4O10], a new mineral from the Kalahari Manganese Field, South Africa: description and crystal structure. Mineralogical Magazine, 58, 663–670.CrossRefGoogle Scholar
Giester, G. and Rieck, B. (1996) Wesselsite, SrCu[Si4O10], a further new gillespite-group mineral from the Kalahari Manganese Field, South Africa. Mineralogical Magazine, 60, 795–798.CrossRefGoogle Scholar
Giester, G., Mikenda, W. and Pertlik, F. (1996) Kleinite from Terlingua, Brewster County, Texas: investigations by single crystal X-ray diffraction, and vibrational spectroscopy. Neues Jahrbuch für Mineralogie, 2, 49–56.Google Scholar
Giester, G., Lengauer, C.L., Pristacz, H., Rieck, B., Topa, D. and von Bezing, K.-L. (2016) Cairncrossite, a new phyllosilicate from the Wessels Mine, Kalahari Manganese Field, South Africa. European Journal of Mineralogy, 28, 495–505.CrossRefGoogle Scholar
Giester, G., Lengauer, C.L., Topa, D., Gutzmer, J. and Von Bezing, K.-L. (2019) Saccoite, IMA 2019-056. CNMNC Newsletter No. 52. Mineralogical Magazine, 83, https://doi.org/10.1180/mgm.2019.73.Google Scholar
Gladstone, J.H. and Dale, T.P. (1863) Researches on the refraction, dispersion, and sensitiveness of liquids. Philosophical Transactions of the Royal Society of London, 153, 317–343.Google Scholar
Gnos, E., Armbruster, T. and Villa, I.M. (2003) Norrishite, K(Mn23+ Li)Si4O10(O)2, an oxymica associated with sugilite from the Wessels Mine, South Africa: Crystal chemistry and 40Ar–39Ar dating. American Mineralogist, 88, 189–194.CrossRefGoogle Scholar
Gunter, M.E., Bandli, B.R., Bloss, F.D., Evans, S.H., Su, S.-C. and Weaver, R. (2004) Results from a McCrone spindle stage short course, a new version of EXCALIBR, and how to build a spindle stage. The Microscope, 52, 23–39.Google Scholar
Gutzmer, J. and Beukes, N.J. (1993) Fault-controlled metasomatic alteration of early Proterozoic sedimentary manganese ores in the Kalahari manganese field, South Africa. Economic Geology, 90, 823–844.CrossRefGoogle Scholar
Gutzmer, J. and Beukes, N.J. (1996) Mineral paragenesis of the Kalahari managanese field, South Africa. Ore Geology Reviews, 11, 405–428.CrossRefGoogle 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, 65–77.CrossRefGoogle Scholar
Mandarino, J.A. (1976) The Gladstone-Dale Relationship – Part I: Derivation of new constants. The Canadian Mineralogist, 14, 498–502.Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale Relationship: Part IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441–450.Google Scholar
Nasdala, L., Akhmadaliev, S., Artac, A., Chanmuang, N. C., Habler, G. and Lenz, C. (2018) Irradiation effects in monazite-(Ce) and zircon: Raman and photoluminescence study of Au-irradiated FIB foils. Physics and Chemistry of Minerals, 45, 855–871.CrossRefGoogle ScholarPubMed
Rieck, B., Pristacz, H. and Giester, G. (2015) Colinowensite, BaCuSi2O6, a new mineral from the Kalahari Manganese Field, South Africa, and new data on wesselsite, SrCuSi4O10. Mineralogical Magazine, 79, 1769–1778.CrossRefGoogle Scholar
Sachs, A. (1905) Der Kleinit, ein hexagonales Quecksilberoxychlorid von Terlingua in Texas. Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften zu Berlin, 1905(2), 1091–1094.Google Scholar
Sheldrick, G.M. (2015) Crystal structure refinement with SHELXL. Acta Crystallographica, C71, 3–8.Google Scholar
Sheldrick, G.M. (2018) SHELXL-2018/3. Universität Göttingen, Göttingen, Germany.Google Scholar
Strunz, H. and Nickel, E.H. (2001) Strunz Mineralogical Tables. Chemical-Structural Mineral Classification System. Ninth Edition, E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany, 870 pp.Google Scholar
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