Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-10T10:22:23.568Z Has data issue: false hasContentIssue false

Leverettite from the Torrecillas mine, Iquique Provence, Chile: the Co-analogue of herbertsmithite

Published online by Cambridge University Press:  05 July 2018

A. R. Kampf*
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA
M. J. Sciberras
Affiliation:
School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith NSW 2750, Australia
P. A. Williams
Affiliation:
School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith NSW 2750, Australia
M. Dini
Affiliation:
Pasaje San Agustin 4045, La Serena, Chile
A. A. Molina Donoso
Affiliation:
Los Algarrobos 2986 - Iquique, Chile
*

Abstract

The new mineral leverettite (IMA 2013-011), ideally Cu3CoCl2(OH)6, was found at the Torrecillas mine, Salar Grande, Iquique Province, Chile, where it occurs as a supergene alteration phase in association with akaganéite, anhydrite, chalcophanite, goethite, halite, manganite, pyrite, quartz and todorokite. Crystals of leverettite are steep rhombohedra to 1 mm with {101} prominent and modified by {001}, sometimes forming V-shaped twins by reflection on {10}. The crystals can also form finger-like, parallel stacked growths along the c axis. The new mineral is medium to deep green in colour and has a light green streak. Crystals are transparent with a vitreous lustre. Mohs hardness is ∼3 and the crystals have a brittle tenacity, a perfect cleavage on {101} and a conchoidal fracture. The measured density is 3.64(2) g cm–3 and calculated density based on the empirical formula is 3.709 g cm–3. Optically, leverettite is uniaxial (–) with ω and ε > 1.8 and exhibits pleochroism with O (bluish green) > E (slightly yellowish green). The empirical formula, determined from electron-microprobe analyses is Cu3(Co0.43Cu0.40Mn0.17Ni0.07Mg0.01)Σ1.08Cl1.87O6.13H6. Leverettite is trigonal (hexagonal), space group Rm, unit-cell parameters a = 6.8436(6) and c = 14.064(1) Å, V = 570.42(8) Å3, Z = 3. The eight strongest X-ray powder diffraction lines are [dobs Å (I)(hkl)]: 5.469(90)(101), 4.701(18)(003), 2.905(22)(021), 2.766(100)(113), 2.269(66)(024), 1.822(26)(033), 1.711(33)(220), 1.383(23)(128). The structure, refined to R1 = 0.023 for 183 Fo > 4σF reflections, shows leverettite to be isostructural with herbertsmithite and gillardite.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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

Braithwaite, R.S.W., Mereiter, K., Paar, W.H. and Clark, A.M. (2004) Herbertsmithite , Cu3Zn(OH)6Cl2, a new species, and the definition of paratacamite. Mineralogical Magazine, 68, 527539.CrossRefGoogle Scholar
Burla, M.C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G.L., De Caro, L., Giacovazzo, C., Polidori, G., and Spagna, R., (2005) SIR2004: an improved tool for crystal structure determination and refinement. Journal of Applied Crystallography, 38, 381388.CrossRefGoogle Scholar
Clissold, M.E., Leverett, P., and Williams, P.A. (2007) The structure of gillardite, the Ni-analogue of herbertsmithite, from Widgiemooltha, Western Australia. The Canadian Mineralogist, 45, 317320.CrossRefGoogle Scholar
Colchester, D.M., Leverett, P., Clissold, M.E., Williams, P.A., Hibbs, D.E. and Nickel, E.H. (2007) Gillardite, Cu3NiCl2(OH)6, a new mineral from the 132 North deposit, Widgiemooltha, Western Australia. Australian Journal of Mineralogy, 13, 1518.Google Scholar
Fleet, M.E. (1975) The crystal structure of paratacamite, Cu2(OH)3Cl. Acta Crystallographica, B31, 183187.CrossRefGoogle Scholar
Gutiérrez, H. (1975) Informe sobre una rápida visita a la mina de arsénico nativo, Torrecillas. Instituto de Investigaciones Geolόgicas, Iquique, Chile.Google Scholar
Higashi, T. (2001) ABSCOR. Rigaku Corporation, Tokyo.Google Scholar
Jambor, J.L., Dutrizac, J.E., Roberts, A.C., Grice, J.D. and Szymański, J.T. (1996) Clinoatacamite, a new polymorph of Cu2(OH)3Cl, and its relationship to paratacamite and “anarakite”. The Canadian Mineralogist, 34, 6172. Kampf, A.R., Sciberras, M.J., Leverett, P., Williams, P.A., Malcherek, T., Schlüter, J., Welch, M., and Dini, M., (2013) Paratacamite - (Mg ) , Cu3(Mg,Cu)Cl2(OH)6; a new substituted basic copper chloride mineral from Camerones, Chile. Mineralogical Magazine, 77, submitted.Google Scholar
Nespolo, M., and Ferraris, G., (2006) The derivation of twin laws in non-merohedric twins. Application to the analysis of hybrid twins. Acta Crystallographica, A62, 336349.CrossRefGoogle Scholar
Oswald, H.R. and Feitknecht, W., (1964) Ü ber Hydroxidhalogenide Me2(OH)3Cl, -Br, -J zweiwertiger Metalle (Me = Mg, Ni, Co, Cu, Fe, Mn). Helvetica Chimica Acta, 47, 272289.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112122.CrossRefGoogle Scholar
Sciberras, M.J., Leverett, P., Williams, P.A., Hibbs, D.E., Downes, P.J., Welch, M.D. and Kampf, A.R (2013) Paratacamite-(Ni), Cu3(Ni,Cu)Cl2(OH)6, a new mineral from Western Australia. Australian Journal of Mineralogy, 17, in press.Google Scholar
Welch, M.D., Sciberras, M.J., Leverett, P., Williams, P.A., Schlüter, J. and Malcherek, T., (2013) A temperature-induced reversible transformation between paratacamite and herbertsmithite. Physics and Chemistry of Minerals, 40, in press.Google Scholar