Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-28T05:54:36.077Z Has data issue: false hasContentIssue false
  • English
  • Français

The crystal structure of cyanotrichite

Published online by Cambridge University Press:  02 January 2018

Stuart J. Mills ,
Andrew G. Christy ,
Fernando Colombo  and
Jason R. Price
Stuart J. Mills*
Affiliation:
Geosciences, Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
Andrew G. Christy
Affiliation:
Centre for Advanced Microscopy and Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200, Australia
Fernando Colombo
Affiliation:
CICTERRA-CONICET and Cátedra de Mineralogía, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sarsfield 1611 (X5016GCA), Córdoba, Argentina
Jason R. Price
Affiliation:
Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

We report the single-crystal average structure of cyanotrichite, Cu4Al2[SO4](OH)12(H2O)2, from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C2/m, with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R1 = 0.0394 for all 584 observed reflections [Fo > 4σFo] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu2Al(OH)6] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO4 tetrahedra and H2O molecules form rods running || b. A hydrogen-bonding scheme is also proposed.

A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4b superstructure with the following unit cell: space group P2/m, a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO4 and H2O in the 4b supercell, it requires that the sequence of species along any given rod is [-SO4-SO4-(H2O)2-(H2O)2-] rather than [-SO4-(H2O)2-SO4-(H2O)2-].

Keywords

cyanotrichitecamerolaitecarbonatecyanotrichitekhaidarkanitemerotypesuperstructurecrystal structuresynchrotron
Type
Research Article
Information
Mineralogical Magazine , Volume 79 , Issue 2 , April 2015 , pp. 321 - 335
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2015

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

Barbier, J., Grew, E.S., Moore, P.B. and Su, S.-C. (1999) Khmaralite, a new beryllium-bearing mineral related to sapphirine: a superstructure resulting from partial ordering of Be, Al and Si on tetrahedral sites. American Mineralogist, 84, 1650–1660.CrossRefGoogle Scholar
Brese, N.D. and O’Keeffe, M. (1991) Bond-valence parametrers for solids. Acta Crystallographica, B47, 192–197.CrossRefGoogle Scholar
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure Database. Acta Crystallographica, B41, 244–247.CrossRefGoogle Scholar
Bruker (2001) SAINT Version 6.02 (includes XPREP and SADABS). Bruker AXS Inc., Madison, Wisconsin, USA. Christy, A.G. (1988) A new 2c superstructure in beryllian sapphirine from Casey Bay, Enderby Land, Antarctica. American Mineralogist, 73, 1134–1137.Google Scholar
Christy, A.G. (2009) A Monte Carlo study of short-and long-range order of tetrahedral cations in sapphirine and khmaralite. American Mineralogist, 94, 270–282.CrossRefGoogle Scholar
Christy, A.G. and Putnis, A. (1988) Planar and line defects in the sapphirine polytypes. Physics and Chemistry of Minerals, 15, 548–558.CrossRefGoogle Scholar
Hager, S.L., Leverett, P. and Williams, P.A. (2009) Possible structural and chemical relationships in the cyanotrichite group. The Canadian Mineralogist, 47, 635–648.CrossRefGoogle Scholar
Hawthorne, F.C., Krivovichev, S.V. and Burns, P.C. (2000) The crystal chemistry of sulfate minerals. Pp. 1–112. in: Sulfate Minerals: Crystallography, Geochemistry and Environmental Significance (C.N. Alpers, J.L. Jambor and D.K. Nordstrom, editors). Reviews in Mineralogy, 40. The Mineralogical Society of America, Washington, DC.Google Scholar
Kabsch, W. (2010) XDS. Acta Crystallographica, D66, 125–132.Google Scholar
Mills, S.J., Kampf, A.R., McDonald, A.M., Bindi, L., Christy, A.G., Kolitsch, U. and Favreau, G. (2013) The crystal structure of parnauite: a copper arsenatesulphate with translational disorder of structural rods. European Journal of Mineralogy, 25, 693–704.CrossRefGoogle Scholar
Mills, S.J., Christy, A.G., Schnyder, C., Favreau, G. and Price, J.R. (2014) The crystal structure of camerolaite and structural variation in the cyanotrichite family of merotypes. Mineralogical Magazine, 78, 1501–1526.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.CrossRefGoogle Scholar