Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-10T08:25:52.314Z Has data issue: false hasContentIssue false
  • English
  • Français

Carlhintzeite, Ca2AlF7·H2O, from the Gigante granitic pegmatite, Córdoba province, Argentina: description and crystal structure

Published online by Cambridge University Press:  05 July 2018

A. R. Kampf ,
F. Colombo  and
J. González del Tánago
A. R. Kampf*
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Blvd, Los Angeles California 90007, USA
F. Colombo
Affiliation:
CICTERRA-CONICET - Cátedra de Geología General, Facultad de Ciencias Exactas, Físicas y Naturales – Pabellón Geología, Universidad Nacional de Córdoba, Vélez Sarsfield 1611, (X5016GCA) Córdoba, Argentina
J. González del Tánago
Affiliation:
Departamento de Petrología y Geoquímica, Facultad de Ciencias Geológicas, Universidad Complutense, 28040 Madrid, Spain
*
*E-mail: akampf@nhm.org
Get access Rights & Permissions [Opens in a new window]

Abstract

Carlhintzeite, Ca2AlF7·H2O, has been found at the Gigante pegmatite, Punilla Department, Córdoba Province, Argentina. It occurs as colourless prismatic crystals up to 0.8 mm long, ubiquitously twinned on {001}. Electron microprobe analyses provided the empirical formula Ca1.98Al1.02F6.24(OH)0.76·H1.62O. A crystal fragment used for the collection of structure data provided the triclinic, C1̄ cell: a = 9.4227(4), b = 6.9670(5), c = 9.2671(7) Å, α = 90.974(6), β = 104.802(5), γ = 90.026(6)°, V = 558.08(7) Å3 and Z = 4. The crystal structure, solved by direct methods and refined to R1 = 0.0322 for 723 Fo > 4σF reflections, is made up of linkages of AlF6 octahedra, CaF8 polyhedra and CaF6(H2O)2 polyhedra. The AlF6 octahedra are isolated from one another, but share polyhedral elements with Ca polyhedra. Most notably, the Al1 octahedron shares trans faces with two CaF8 polyhedra and the Al2 octahedron shares trans edges with two CaF6(H2O)2 polyhedra. The linkage of the Ca polyhedra alone can be described as a framework in which edge-sharing chains along b are cross-linked by edge-sharing. Edge-sharing chains of Ca polyhedra along b in the carlhintzeite structure are similar to those along c in the structures of gearksutite, CaAlF4(OH)·(H2O), and prosopite, CaAl2F4(OH)4.

Keywords

carlhintzeitegearksutiteprosopitecrystal structureCórdobaArgentina
Type
Research Article
Information
Mineralogical Magazine , Volume 74 , Issue 4 , August 2010 , pp. 623 - 632
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2010

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

Altomare, A., Cascarano, G., Giacovazzo, C, Guagliardi, A., Burla, M.C., Polidori, G. and Camalli, M. (1994) SIR92 — a program for automatic solution of crystal structures by direct methods. Journal of Applied Crystallography, 27, 435.Google Scholar
Bortolozzi, G., Ciriotti, M.E., Galli, E. and Bonacina, E. (2007) Carlhintzeite e cowlesite della Sardegna: primi ritrovamenti italiani. Micro (UK report), 1/2007, 33–38.Google Scholar
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Ada Crystallographica, B41, 244–247.Google Scholar
Dill, H.G., Gerdes, A., Melcher, F., Weber, B., Techmer, T. and Fill, M. (2008) Die Hagendorfer Pegmatitprovinz (Oberpfalz / Deutschland) aus Sedimentologisch-Geomorphologischer und Mineralogisch-Lagerstättenkundlicher Sicht. Mitteilungen der Österreichischen Mineralogischen Gesellschqft, 154, 7–34.Google Scholar
Dunn, P.J., Peacor, D.R. and Sturman, B.D. (1979) Carlhintzeite, a new calcium aluminum fluoride hydrate from the Hagendorf pegmatites, Bavaria, Germany. The Canadian Mineralogist, 17, 103–105.Google Scholar
Galliski, M.A. (1999) Distrito pegmatítico Punilla. In: Zappettini E.O. (Ed.) Recursos Minerales de la Repblica Argentina. Instituto de Geologia y Recursos Minerales. SEGEMAR, Anales, 35, 547–550.Google Scholar
Kampf, A.R., Colombo, F. and González del Tánago, J. (2010a) Gayite, a new dufrénite-group mineral from the Gigante granitic pegmatite, Cordoba province, Argentina. American Mineralogist, 95, 386–391.CrossRefGoogle Scholar
Kampf, A.R., Colombo, F., Simmons, W.B., Falster, A.U. and Nizamoff, J.W. (20106) Galliskiite, Ca4Al2(PO4)2F8·5H2O, a new mineral from the Gigante granitic pegmatite, Cordoba province, Argentina. American Mineralogist, 95, 392–396.CrossRefGoogle Scholar
Marchetti, F. and Perchiazzi, N. (2000) The crystal structure of gearksutite, CaAlF4(OH)-H2O. American Mineralogist, 85, 231–235.CrossRefGoogle Scholar
Novikova, M.I., Sidorenko, G.A. and Kuznetsova, M.N. (1966) Yaroslavite — a new calcium aluminum fluoride. Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva, 95, 39–44.Google Scholar
Pudovkina, Z.V., Chernitsova, N.M. and Pyatenko, Yu.A. (1973) Refinement of the crystalline structure of prosopite CaAl2F4(OH)4 . Journal of Structural Chemistry, 14, 345–347.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) SHELXL97 - Program for the refinement of crystal structures. University of Gottigen, Germany.Google Scholar
Wegner, R., Pollmann, H., Witzke, T. and Schuckmann, W. (1998) Colquiriite, carlhintzeite, ralstonite and pachnolite from Serra Blanca pegmatite, Brazil. 17th General Meeting of the International Mineralogical Association, Abstract volume, A151, Toronto, Canada.Google Scholar
Supplementary material: File

Kampf et al. supplementary material

Cif file

Download Kampf et al. supplementary material(File)
File 18 KB