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Agmantinite, Ag2MnSnS4, a new mineral with a wurtzite derivative structure from the Uchucchacua polymetallic deposit, Lima Department, Peru

Published online by Cambridge University Press:  02 July 2018

Frank N. Keutsch*
Affiliation:
John A. Paulson School of Engineering and Applied Sciences and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
Dan Topa
Affiliation:
Naturhistorisches Museum-Wien, Burgring 7, 1010 Wien, Austria
Rie Takagi Fredrickson
Affiliation:
Department of Chemistry, University of Wisconsin-Madison, WI 53706, USA
Emil Makovicky
Affiliation:
Institute for Geoscience and Natural Resource Management, Østervoldgade 10, DK-1350, Copenhagen K, Denmark
Werner H. Paar
Affiliation:
Fachbereich Chemie und Physik der Materialien, University, Hellbrunnerstr. 34, A-5020 Salzburg, Austria (Department of chemistry and physics of materials)
*
*Author for correspondence: Frank N. Keutsch, Email: [email protected]

Abstract

Agmantinite, ideally Ag2MnSnS4, is a new mineral from the Uchucchacua polymetallic deposit, Oyon district, Catajambo, Lima Department, Peru. It occurs as orange–red crystals up to 100 μm across. Agmantinite is translucent with adamantine lustre and possesses a red streak. It is brittle. Neither fracture nor cleavage were observed. Based on the empirical formula the calculated density is 4.574 g/cm3. On the basis of chemically similar compounds the Mohs hardness is estimated at between 2 to 2½. In plane-polarised light agmantinite is white with red internal reflections. It is weakly bireflectant with no observable pleochroism with red internal reflections. Between crossed polars, agmantinite is weakly anisotropic with reddish brown to greenish grey rotation tints. The reflectances (Rmin and Rmax) for the four standard wavelengths are: 19.7 and 22.0 (470 nm); 20.5 and 23.2 (546 nm); 21.7 and 2.49 (589 nm); and 20.6 and 23.6 (650 nm), respectively.

Agmantinite is orthorhombic, space group P21nm, with unit-cell parameters: a = 6.632(2), b = 6.922(2), c = 8.156(2) Å, V = 374.41(17) Å3, a:b:c 0.958:1:1.178 and Z = 2. The crystal structure was refined to R = 0.0575 for 519 reflections with I > 2σ(I). Agmantinite is the first known mineral of ${M}_{\rm 2}^{\rm I} $MIIMIVS4 type that is derived from wurtzite rather than sphalerite by ordered substitution of Zn, analogous to the substitution pattern for deriving stannite from sphalerite. The six strongest X-ray powder-diffraction lines derived from single-crystal X-ray diffraction data [d in Å (intensity)] are: 3.51 (s), 3.32 (w), 3.11 (vs), 2.42 (w), 2.04 (m) and 1.88 (m). The empirical formula (based on 8 apfu) is (Ag1.94Cu0.03)Σ1.97(Mn0.98Zn0.05)Σ1.03Sn0.97S4.03.The crystal structure-derived formula is Ag2(Mn0.69Zn0.31)Σ1.00SnS4 and the simplified formula is Ag2MnSnS4.

The name is for the composition and the new mineral and mineral name have been approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2014-083).

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

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Footnotes

Associate Editor: David Hibbs

References

Bernert, T. and Pfitzner, A. (2005) Cu2MnMIVS4 (MIV = Si, Ge, Sn) – analysis of crystal structures and tetrahedra volumes of normal tetrahedral compounds. Zeitschrift für Kristallographie, 220, 968972.Google Scholar
Bindi, L., Keutsch, F.N. and Bonazzi, P. (2012) Menchettiite, AgPb2.40Mn1.60Sb3As2S12, a new sulfosalt belonging to the lillianite series from the Uchucchacua polymetallic deposit, Lima Department, Peru. American Mineralogist, 97, 440446.Google Scholar
Bindi, L., Keutsch, F.N., Morana, M. and Zaccarini, F. (2017) Spryite, Ag8(As3+0.5As5+0.5)S6: structure determination and inferred absence of superionic conduction of the first As3+-bearing argyrodite. Physics and Chemistry of Minerals, 44, 7582.Google Scholar
Bindi, L., Biagioni, C. and Keutsch, F.N. (2018) Oyonite, Ag3Mn2Pb4Sb7As4S24, a new member of the lillianite homologous series from the Uchucchacua base-metal deposit, Oyon District, Peru. Minerals, 8, 192.Google Scholar
Bonazzi, P, Keutsch, F.N. and Bindi, L. (2012) Manganoquadratite, AgMnAsS3, a new manganese-bearing sulfosalt from the Uchucchacua polymetallic deposit, Lima Department, Peru: Description and crystal structure. American Mineralogist, 97, 11991205.Google Scholar
Bruker AXS (1997) SHELXTL, Version 5.1. Bruker AXS, Inc., Madison, WI 53719, USA.Google Scholar
Bruker AXS (1998 a) SMART, Version 5.0. Bruker AXS, Inc., Madison, WI 53719, USA.Google Scholar
Bruker AXS (1998 b) SAINT, Version 5.0. Bruker AXS, Inc., Madison, WI 53719, USA.Google Scholar
Caye, R., Laurent, Y., Picot, P., Pierrot, R. and Levy, C. (1968) La hocartite, Ag2SnFeS4, une nouvelle espece minerale. Bulletin de la Société française de Minéralogie et de Cristallographie, 91, 383387.Google Scholar
Garin, J. and Parthé, E. (1972) The crystal structure of Cu3PSe4 and other ternary normal tetrahedral structure compounds with composition 13564. Acta Crystallographica, B28, 36723674.Google Scholar
Hall, S.R., Szymanski, J.T. and Stewart, J.M. (1978) Kësterite, Cu2(Zn,Fe)SnS4, and stannite, Cu2(Fe,Zn)SnS4, structurally similar but distinct minerals. The Canadian Mineralogist, 16, 131137.Google Scholar
Johan, Z. and Picot, P. (1982) La pirquitasite, Ag2ZnSnS4, un nouveau member du groupe de la stannite. Bulletin de Minéralogie, 105, 229235.Google Scholar
Kaplunnik, L.N., Pobedimskaya, E.A. and Belov, N.V. (1977) Crystal structure of velikite Cu3.75Hg1.75Sn2S8. Soviet Physics Crystallography, 22, 99100.Google Scholar
Karanovic, L., Cvetkovic, L., Balić-Žunić, T. and Makovicky, E. (2002) Crystal and absolute structure of enargite form Bor (Serbia). Neues Jahrbuch fuer Mineralogie-Monatshefte, 6, 241253.Google Scholar
Keutsch, F.N., Topa, D., Takagi Fredrickson, R., Makovicky, E. and Paar, W. (2015) Agmantinite, IMA 2014-083. CNMNC Newsletter No. 23, February 2015, page 57; Mineralogical Magazine, 79, 5158.Google Scholar
Keutsch, F.N., Topa, D. and Makovicky, E. (2017) Hyršlite, IMA 2016-097. CNMNC Newsletter No. 36, April 2017, page 404; Mineralogical Magazine, 81, 403409.Google Scholar
Kissin, S.A. and Owens, D.R. (1989) The relatives of stannite in the light of new data. The Canadian Mineralogist, 27, 673688.Google Scholar
Kraus, W. and Nolze, G. (1999) Powder Cell for Windows, version 2.3. BAM, Berlin, Germany.Google Scholar
Marumo, F. and Nowacki, W. (1967) A refinement of the crystal structure of luzonite, Cu3AsS4 Zeitschrift fur Kristallographie 124, 18.Google Scholar
McDonald, A.M., Stanley, C.J., Ross, K.C. and Nestola, F. (2016) Zincobriartite, IMA 2015-094. CNMNC Newsletter No. 29, February 2016, page 203; Mineralogical Magazine, 80, 199205.Google Scholar
Moëlo, Y., Oudin, E., Picot, P. and Caye, R. (1984) L'uchucchacuaite, AgMnPb3Sb5S12, une nouvelle espece minerale de la serie de l'andorite. Bullettin de Minéralogie, 107, 597604.Google Scholar
Murciego, A., Pascua, M.I., Babkine, J., Dusausoy, Y., Medenbach, O. and Bernhardt, H.-J. (1999) Barquillite, Cu2(Cd, Fe)GeS4, a new mineral from the Barquilla deposit, Salamanca, Spain. European Journal of Mineralogy, 11, 111117.Google Scholar
Oudin, E., Picot, P., Pillard, F., Moëlo, Y., Burke, E. and Zakrzewski, A. (1982) La benavidesite, Pb4(Mn,Fe)Sb6S14, un nouveau mineral de la serie de la jamesonite. Bullettin de Minéralogie, 105, 166169.Google Scholar
Parthé, E., Yvon, K. and Deitch, R.H. (1969) The crystal structure of Cu2CdGeS4 and other quaternary normal tetrahedral structure compounds. Acta Crystallographica, B25, 11641174.Google Scholar
Schumer, B.N., Downs, R.T., Domanik, K.J., Andrade, M.B. and Origlieri, M.J. (2013) Pirquitasite, Ag2ZnSnS4. Acta Crystallographica, E69, i8i9.Google Scholar
Sheldrick, G.M. (1997 a) SHELXS-97. A computer program for crystal structure determination. University of Göttingen, Germany.Google Scholar
Sheldrick, G.M. (1997 b) SHELXL-97. A computer program for crystal structure refinement. University of Göttingen, Germany.Google Scholar
Szymanski, J.T. (1978) The crystal structure of Černýite, Cu2CdSnS4, a cadmium analogue of stannite. The Canadian Mineralogist, 16, 147151.Google Scholar
Topa, D., Fredrickson, R.T. and Stanley, C. (2014) Keutschite, IMA 2014-038. CNMNC Newsletter No. 21, August 2014, page 804. Mineralogical Magazine, 78, 797804.Google Scholar
Wintenberger, M. (1979) Etude de la structure cristallographique et magnetique de Cu2FeGeS4 et remarque sur la structure magnetique de Cu2MnSnS4. Materials Research Bulletin, 14, 11951202.Google Scholar
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