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Chongite, Ca3Mg2(AsO4)2(AsO3OH)2·4H2O, a new arsenate member of the hureaulite group from the Torrecillas mine, Iquique Province, Chile

Published online by Cambridge University Press:  02 January 2018

Anthony R. Kampf ,
Barbara P. Nash ,
Maurizio Dini  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
Maurizio Dini
Affiliation:
Pasaje San Agustin 4045, La Serena, Chile
Arturo A. Molina Donoso
Affiliation:
Los Algarrobos 2986, Iquique, Chile
*
*E-mail: akampf@nhm.org
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Abstract

The new mineral chongite (IMA2015–039), Ca3Mg2(AsO4)2(AsO3OH)2.4H2O, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with native arsenic, arsenolite, gajardoite, talmessite and torrecillasite. Chongite occurs as prismatic crystals up to ∼1 mm long grouped in tightly intergrown radial aggregates up to 2 mm in diameter. Crystals are transparent, with vitreous lustre and white streak. The Mohs hardness is ∼3½, tenacity is brittle and fracture is conchoidal. Cleavage is good on ﹛100﹜. The measured density is 3.09(2) g/cm3 and the calculated density is 3.087 g/cm3. Optically, chongite is biaxial (-) with α = 1.612(1), β= 1.626(1), γ= 1.635(1) and 2V = 76.9(1)° (measured in white light). Dispersion is r < v, distinct. The optical orientation is X= b;Z^a = 27° in obtuse angle β. The mineral is slowly soluble in dilute HCl at room temperature. The empirical formula, determined from electron-microprobe analyses, is (Ca2.90Mg1.93Mn0.14)Σ4.97As4O20H10.07. Chongite is monoclinic, die, a = 18.5879(6), b = 9.3660(3), c = 9.9622(7) Å, β = 96.916(7)°, V= 1721.75(14) Å3 and Z=4. The eight strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 8.35(29)(110), 4.644(62) (3ˉ11,020,400,2̄02), 4.396(26)(311), 3.372(62)(022,312,5̄11), 3.275(100)(420,22ˉ2,421), 3.113(57)(222), 2.384(30)(711,530,7̄12) and 1.7990(22)(9̄13,334,5̄34). The structure determination (R1 = 1.56% for 1849 Fo > 4σF reflections) confirms that chongite is a member of the hureaulite group.

Keywords

chongitenew mineralarsenatecrystal structurehureaulite groupTorrecillas mineChile
Type
Research Article
Information
Mineralogical Magazine , Volume 80 , Issue 7 , December 2016 , pp. 1255 - 1263
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

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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.CrossRefGoogle Scholar
Burla, M.C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G.L., Giacovazzo, C., Mallamo, M., Mazzone, A., Polidori, G. and Spagna, R. (2012) SIR2011: a new package for crystal structure determination and refinement. Journal of Applied Crystallography, 45, 357–361.CrossRefGoogle 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, 205—218.CrossRefGoogle Scholar
Elliott, P., Turner, P., Jensen, P., Kolitsch, U. and Pring, A. (2009) Description and crystal structure of nyholmite, a new mineral related to hureaulite, from Broken Hill, New South Wales, Australia. Mineralogical Magazine, 73, 723–735.CrossRefGoogle Scholar
Ferraris, G. and Abbona, F. (1972) The crystal structure of Ca5(HAsO4)2(AsO4)2-4H2O (sainfeldite). Bulletin de la Société Française de Minéralogie et de Cristallographie, 95, 33–41.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. (2009) Miguelromeroite, the Mn analogue of sainfeldite, and redefinition of villyaellenite as an ordered intermediate in the sainfeldite-miguelromeroite series. American Mineralogist, 94, 1535—1540.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 Co-analogue 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
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2014a) Torrecillasite, Na(As,Sb)3 +4O6Cl, a new mineral from the Torrecillas mine, Iquique Province, Chile: description and crystal structure. Mineralogical Magazine, 78, 747–755.CrossRefGoogle Scholar
Kampf, A.R., Mills, S.J., Hatert, F., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2014b) 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.CrossRefGoogle Scholar
Kampf, A.R., Nash, B.P., Dini, M. and Molina Donoso, A.A. (2016) Gajardoite, KCa0.5As4 +O6Cl2'5H2O, anew mineral related to lucabindiite and torrecillasite from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 80, 1265—1272.CrossRefGoogle 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, 1307–1324.CrossRefGoogle Scholar
Moore, P.B. and Araki, T (1973) Hureaulite, Mn2 (H2O)4[PO3(OH)]2[PO4]2: Its atomic arrangement. American Mineralogist, 58, 302—307.Google Scholar
Mortimer, C., Saric, N. and Cáceres, R. (1971) Apuntes sobre algunas minas de la región costera de la provincia de Tarapacá. Instituto de Investigaciones Geológicas, Santiago de Chile, Chile.Google Scholar
Ondruš, P., Veselovský, F., Skála, R., Císarová, I., Hloušek, J., Frýda, J., Vavrín, I., Cejka, J. and Gabašová, A. (1997) New naturally occurring phases of secondary origin from Jáchymov (Joachimsthal). Journal of the Czech Geological Society, 42, 77—108.Google Scholar
Pierrot, R. and Schubnel, H.-J. (1972) L'irhtemite, un nouvel arséniate hydrate de calcium et magnésium. Bulletin de la Société Française de Minéralogie et de Cristallographie, 95, 365–370.CrossRefGoogle Scholar
Pimentel, F (1978) Proyecto Arsenico Torrecillas.Instituto de Investigaciones Geológicas, Iquique, Chile.Google Scholar
Pouchou, J.-L. andPichoir, F (1991) Quantitative analysis of homogeneous or stratified microvolumes applying the model “PAP.” Pp. 3l-75 in: Electron Probe Quantitatio.(K.F.J. Heinrich and D.E. Newbury, editors). Plenum Press, New York.CrossRefGoogle Scholar
Sheldrick, G.M. (2015) Crystal structure refinement with SHELXL. Acta Crystallographica,C71, 3–8.Google Scholar
Smith, D.G.W.and Nickel, E.H. (2007) A system of codification for unnamed minerals: Report of the Subcommittee for Unnamed Minerals of the IMA Commission on New Minerals, Nomenclature and Classification. The Canadian Mineralogist, 45, 983–1055.CrossRefGoogle Scholar