Hostname: page-component-848d4c4894-4hhp2 Total loading time: 0 Render date: 2024-05-07T20:55:58.942Z Has data issue: false hasContentIssue false
  • English
  • Français

Magnesiocanutite, NaMnMg2[AsO4]2[AsO2(OH)2], a new protonated alluaudite-group mineral from the Torrecillas mine, Iquique Province, Chile

Published online by Cambridge University Press:  26 January 2018

Anthony R. Kampf ,
Barbara P. Nash ,
Dini Maurizio  and
Arturo A. Molina Donoso
Anthony R. Kampf*
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA
Barbara P. Nash
Affiliation:
Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA
Dini Maurizio
Affiliation:
Pasaje San Agustin 4045, La Serena, Chile
Arturo A. Molina Donoso
Affiliation:
Los Algarrobos 2986, Iquique, Chile
*
* E-mail: akampf@nhm.org
Get access Rights & Permissions [Opens in a new window]

Abstract

The new mineral magnesiocanutite (IMA2016-057), NaMnMg2[AsO4]2[AsO2(OH)2], was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary phase in association with anhydrite, canutite, halite, lavendulan and magnesiokoritnigite. Magnesiocanutite occurs as pale brownish-pink to rose-pink, lozenge-shaped tablets that are often grouped in tightly intergrown aggregates. The crystal forms are {110} and {102}. Crystals are transparent, with vitreous lustre and white to very pale pink streak. The Mohs hardness is 2½, tenacity is brittle, and the fracture is splintery. Crystals exhibit two perfect cleavages: {010} and {101}. The calculated density is 3.957 g/cm3. Optically, magnesiocanutite is biaxial (+), with α = 1.689(2), β = 1.700(2), γ = 1.730(2) (measured in white light); 2Vmeas. = 64.3(4)°; slight dispersion, r <v; orientation Z = b; X ∧ a = 15° in obtuse angle β. The mineral is slowly soluble in dilute HCl at room temperature. Electron-microprobe analyses, provided Na2O 5.44, CaO 0.26, MgO 8.84, MnO 18.45, CoO 1.47, CuO 2.13, As2O5 59.51, H2O(calc) 2.86, total 98.96 wt.%. Magnesiocanutite is monoclinic, C2/c, a = 12.2514(8), b = 12.4980(9), c = 6.8345(5) Å, β = 113.167(8)°, V = 962.10(13) Å3 and Z = 4. The eight strongest powder X-ray diffraction lines are [dobs Å(I )(hkl)]: 6.25(42)(020), 3.566(43)(310,1̄31), 3.262(96)(1̄12), 3.120(59)(002,131,040,221), 2.787(93)(400,022,041,330), 2.718(100) (4̄21,240,112,402), 2.641(42)(1̄32) and 1.5026(43)(multiple). Magnesiocanutite has a protonated alluaudite-type structure (R1 = 2.59% for 789 Fo > 4σF reflections) and is the Mg analogue of canutite. Using the results of both the microprobe analyses and structure refinement, the structurally based empirical formula is Na(Mn0.78Mg0.22)Σ1.00(Mg1.04Mn0.70Cu0.15Co0.11)Σ2.00[AsO4]2[AsO2(OH)2].

Keywords

magnesiocanutitenew mineralcanutitearsenatealluaudite groupcrystal structureTorrecillas mineIquique ProvinceChile
Type
Research Article
Information
Mineralogical Magazine , Volume 81 , Issue 6 , December 2017 , pp. 1523 - 1531
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2017

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.)

References

Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244–247.Google Scholar
Cooper, M.A., Hawthorne, F.C., Ball, N.A., Ramik, R.A. and Roberts, A.C. (2009) Groatite, NaCaMn2þ 2 (PO4) [PO3(OH)]2, a new mineral species of the alluaudite group from the Tanco pegmatite, Bernic Lake, Manitoba, Canada: description and crystal structure. Canadian Mineralogist, 47, 1225–1235.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
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., Sciberras, M.J., Williams, P.A., Dini, M. and Molina Donoso, A.A. (2013a) Leverettite from the Torrecillas mine, Iquique Provence, Chile: the Coanalogue of herbertsmithite. Mineralogical Magazine, 77, 3047–3054.Google Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A. A. (2013b) Magnesiokoritnigite, Mg(AsO3OH)·H2O, from the Torrecillas mine, Iquique Province, Chile: the Mg-analogue of koritnigite. Mineralogical Magazine, 77, 3081–3092.Google Scholar
A.R., Kampf, Mills, S.J., Hatert, F., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2014a) Canutite, NaMn3[AsO4]2[AsO2(OH)2], a new protonated alluaudite-group mineral from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 78, 787–795.Google Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A. A. (2014b) Torrecillasite, Na(As,Sb)3+ 4 O6Cl, a new mineral from the Torrecillas mine, Iquique Province, Chile: description and crystal structure. Mineralogical Magazine, 78, 747–755.Google Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2016a) Chongite, Ca3Mg2(AsO4)2 (AsO3OH)2·4H2O, a new arsenate member of the hureaulite group from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 80, 1255–1263.Google Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A. A. (2016b) Gajardoite, KCa0.5As3þ 4 O6Cl2·5H2O, a new mineral related to lucabindiite and torrecillasite from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 80, 1265–1272.Google Scholar
Kampf, A.R., Mills, S.J., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2017a) Currierite, Na4Ca3MgAl4 (AsO3OH)12·9H2O, a new acid arsenate with ferrinatrite- like heteropolyhedral chains from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 81, 1141–1149.Google Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A. A. (2017b) Juansilvaite, Na5Al3[AsO3(OH)]4 [AsO2(OH)2]2(SO4)2·4H2O, a new arsenate-sulfate from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 81, 619–628.Google Scholar
Keller, P. and Hess, H. (1988) Die kristallstrukturen von O’Danielit, Na(Zn,Mg)3H2(AsO4)3, und Johillerit N. (Mg,Zn)3Cu(AsO4)3. Neues Jahrbuch für Mineralogie, Monatshefte, 1988, 395–404.Google Scholar
Krivovichev, S.V., Vergasova, L.P., Filatov, S.K., Rybin, D.S., Britvin, S.N. and Ananiev, V.V. (2013) Hatertite, Na2(Ca,Na)(Fe3+,Cu)2(AsO4)3, a new alluauditegroup mineral from Tolbachik fumaroles, Kamchatka peninsula, Russia. European Journal of Mineralogy, 25, 683–691.CrossRefGoogle Scholar
Mandarino, J.A. (2007) The Gladstone–Dale compatibility of minerals and its use in selecting mineral species for further study. Canadian Mineralogist, 45, 1307–1324.CrossRefGoogle Scholar
Pouchou, J.-L. and Pichoir, F. (1991) Quantitative analysis of homogeneous or stratified microvolumes applying the model “PAP.” Pp. 3l–75 in: Electron Probe Quantitation (Heinrich, K.F.J. and Newbury, D.E., editors). Plenum Press, New York.Google Scholar
Sheldrick, G.M. (2015) Crystal structure refinement with SHELXL. Acta Crystallographica, C71, 3–8.Google Scholar
Wood, R.M. and Palenik, G.J. (1999) Bond valence sums in coordination chemistry. Sodium-oxygen complexes. Inorganic Chemistry, 38, 3926–3930.CrossRefGoogle Scholar
Wright, S.E., Foley, J.A. and Hughes, J.M. (2001) Optimization of site occupancies in minerals using quadratic programming. American Mineralogist, 85, 524–531.CrossRefGoogle Scholar