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Krásnoite, the fluorophosphate analogue of perhamite, from the Huber open pit, Czech Republic and the Silver Coin mine, Nevada, USA

Published online by Cambridge University Press:  05 July 2018

S. J. Mills*
Affiliation:
Geosciences, Museum Victoria, GPO Box 666, Melbourne 3001, Australia
J. Sejkora
Affiliation:
Department of Mineralogy and Petrology, National Museum Prague, Vaclavské nám. 68, CZ-115 79 Praha 1, Czech Republic
A. R. Kampf
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA
I. E. Grey
Affiliation:
CSIRO Process Science and Engineering, Box 312, Clayton South, Victoria 3169, Australia
T. J. Bastow
Affiliation:
CSIRO Materials Science and Engineering, Private Bag 33, Rosebank MDC, Clayton, Victoria 3169, Australia
N. A. Ball
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
P. M. Adams
Affiliation:
126 South Helberta Avenue, #2, Redondo Beach, California 90277, USA
M. Raudsepp
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
M. A. Cooper
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada

Abstract

Krásnoite is a new mineral (IMA2011-040) from the Huber open pit, Krásno ore district, Czech Republic and the Silver Coin mine, Nevada, USA. Krásnoite is the fluorophosphate analogue of perhamite. Krásnoite occurs as compact to finely crystalline aggregates, balls and rosette-like clusters up to 1 mm across. Individual crystals are platy, show a hexagonal outline and can reach 0.1 mm on edge at Krásno and 0.4 mm at Silver Coin. At both localities, krásnoite occurs very late in phosphaterich paragenetic sequences. Krásnoite crystals are partly transparent with a typically pearly lustre, but can also appear greasy (Krásno) or dull (Silver Coin). The streak is white and the hardness is 5 on the Mohs scale. Crystals are brittle, have an irregular fracture, one imperfect cleavage on {001} and are not fluorescent under SW and LW ultraviolet light. Penetration twinning ⊥ {001} is common. The density for both Krásno and Silver Coin material is 2.48(4) g cm–3, measured by the sink–float method in an aqueous solution of sodium polytungstate. The calculated density is 2.476 g cm–3 (Krásno). Krásnoite crystals are uniaxial (+), with ω = 1.548(2) and ε = 1.549(2) (Krásno) and ω = 1.541(1) and ε = 1.543(1) (Silver Coin). The simplified formula of krásnoite is: Ca3Al7.7Si3P4O23.5(OH)12.1F2·8H2O. Krásnoite is trigonal, space group Pm1, with a = 6.9956(4), c = 20.200(2) Å, V = 856.09(9) Å3 and Z = 3. Raman and infrared spectroscopy, coupled with magic-angle spinning nuclear magnetic resonance (MAS–NMR) spectrometry, confirmed the presence of PO3F, PO4, SiO4, H2O and OH in the crystal structure of krásnoite.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

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References

Burnham, C.W. (1962) Lattice constant refinement. Carnegie Institute Washington Yea. Book, 61, 132135 Google Scholar
Cortesogno, L., Gaggero, L. and Lucchetti, G. (1987) Phosphate mineralizations in a Permo-Triassic sequence (Giogo di Toirano, Italy). Neues Jahrbuch für Mineralogie, Monatshefte, 1987, 305313 Google Scholar
Dunn, P.J. and Appleman, D.E. (1977) Perhamite, a new calcium aluminium silico-phosphate mineral, and a re-examination of viseite. Mineralogica. Magazine, 41, 437442 Google Scholar
Farmer, V.C. (1974) The Infrared Spectra of Minerals. Mineralogical Society Monograph, 4. Mineralogical Society of Great Britain & Ireland, London, 539 pp.Google Scholar
Goldberg, P.S. and Nathan, Y. (1975) The phosphate mineralogy of ele-Tabun cave, Mount Carmel, Israel. Mineralogical Magazine, 40, 253258.CrossRefGoogle Scholar
Jambor, J.L. (1999) Nomenclature of the alunite supergroup. The Canadia. Mineralogist, 37, 13231341 Google Scholar
Kampf, A.R., Adams, P.M., Kolitsch, U. and Steele, I.M. (2009) Meurigite-Na, a new species, and the relationship between phosphofibrite and meurigite. American Mineralogist, 94, 720727.CrossRefGoogle Scholar
Mills, S.J. (2003) A note on perhamite from the Moculta (Klemms) phosphate quarry, South Australia. Australian Journal of Mineralogy, 9, 4345.Google Scholar
Mills, S., Grey, I., Mumme, G. and Bordet, P. (2006) The crystal structure of perhamite. Mineralogica. Magazine, 70, 201209 Google Scholar
Mills, S.J., Hatert, F., Nickel, E.H. and Ferraris, G. (2009) The standardisation of mineral group hierarchies: application to recent nomenclature proposals. Europea. Journal of Mineralogy, 21, 10731080 CrossRefGoogle Scholar
Mills, S.J., Kampf, A.R., Sejkora, J., Adams, P.M., Birch, W.D. and Plášil, J. (2011) Iangreyite: a new secondary phosphate closely related to perhamite. Mineralogica. Magazine, 75, 327336 Google Scholar
Ondruš, P. (1993) ZDS - a computer program for analysis of X-ray powder diffraction patterns. Materials Science Forum, 133136 297-300.CrossRefGoogle Scholar
Sejkora, J., Š koda, R. and Ondruš, P. (2006a) New naturally occurring mineral phases from the Krásno- Horní Slavkov area, western Bohemia, Czech Republic. Journal of the Czech Geological Society, 51, 159187 Google Scholar
Sejkora, J., Š koda, R., Ondruš, P., Beran, P. and Sü sser, C. (2006b) Mineralogy of phosphate accumulations in the Huber stock, Krásno ore district, Slavkovský les area, Czech Republic. Journal of the Czech Geological Society, 51, 103147.Google Scholar
Sejkora, J., Plášil, J. and Filip, J. (2011) Plimerite from Krásno near Horní Slavkov ore district, Czech Republic. Journal of Geosciences, 56, 215229 Google Scholar
Tait, K.T., Barkley, M.C., Thompson, R.M., Origlieri, M.J., Evans, S.H., Prewitt, C.T. and Yang, H. (2011) Bobdownsite, a new mineral species from the Big Fish River, Yukon, Canada, and its structural relationship with whitlockite-type compounds. The Canadian Mineralogist, 49, 10651078.CrossRefGoogle Scholar
Thomssen, D. and Wise, W.S. (2004) Special list: Silver Coin Mine, Iron Point district, Edna Mountains, Humboldt Co., Nevada, USA. International Micromounter’s Journal, 13, 78..Google Scholar
Triplehorn, D.M. and Bohor, B.F. (1983) Goyazite in kaolinitic altered tuff beds of Cretaceous age near Denver, Colorado. Clays and Clay Minerals, 31, 299304.CrossRefGoogle Scholar