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Jahnsite-(CaMnZn) from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, and structural flexibility of jahnsite-group minerals

Published online by Cambridge University Press:  08 May 2020

Ian E. Grey*
Affiliation:
CSIRO Mineral Resources, Private Bag 10, Clayton South, Victoria3169, Australia
Erich Keck
Affiliation:
Algunderweg 3, D-92694Etzenricht, Germany
Anthony R. Kampf
Affiliation:
Mineral Sciences Dept., Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA90007, USA
Colin M. MacRae
Affiliation:
CSIRO Mineral Resources, Private Bag 10, Clayton South, Victoria3169, Australia
John D. Cashion
Affiliation:
Monash University, School of Physics and Astronomy, Victoria3800, Australia
A. Matt Glenn
Affiliation:
CSIRO Mineral Resources, Private Bag 10, Clayton South, Victoria3169, Australia
*
*Author for correspondence: Ian E. Grey, Email: Ian.Grey@csiro.au

Abstract

Jahnsite-(CaMnZn), CaMn2+Zn2Fe3+2(PO4)4(OH)2⋅8H2O, is a new jahnsite-group mineral associated with alteration of phosphophyllite at the Hagendorf-Süd pegmatite, Bavaria. It forms as thin yellow crusts and brown epitactic growths on altered phosphophyllite, both of which comprise lath-like crystals in orthogonal orientation, up to 100 μm long. The crystals contain intergrowths of jahnsite-(CaMnZn) and jahnsite-(CaMnMn) on a scale of ~50 μm. The calculated density is 2.87 g cm−3 based on the empirical formula. Optically it is biaxial (–), with α = 1.675(2), β = 1.686(2) and γ = 1.691(2) (white light). The calculated 2V is 68°. Dispersion could not be observed, and the optical orientation is Z = b. Pleochroism was imperceptible. Electron microprobe analyses together with results from Mössbauer spectroscopy gives the formula (Ca0.59Mn0.24)Σ0.83Mn(Zn0.74Mn2+0.48Mg0.18Fe2+0.13Fe3+0.47)Σ2Fe3+2(P0.995O4)4(OH)2.03(H2O)7.97.

Jahnsite-(CaMnZn) is monoclinic, P2/a, with a = 15.059(1), b = 7.1885(6), c = 10.031(2) Å, β = 111.239(8)° and V = 1012.1(2) Å3. The recent International Mineralogical Association approved nomenclature system for jahnsite-group minerals was applied to establish jahnsite-(CaMnZn) from the empirical formula. The structural flexibility of jahnsite-group minerals to accommodate cations of quite different sizes in the X and M1 sites is discussed in terms of rotations about the 7 Å axis of two independent octahedra centred at the M3 sites.

Type
Article
Copyright
Copyright © Mineralogical Society of Great Britain and Ireland 2020

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Footnotes

Associate Editor: Charles A. Geiger

References

Cagliotti, G., Paoletti, A. and Ricca, F.P. (1958) Choice of collimators for a crystal spectrometer for neutron diffraction. Nuclear Instruments, 3, 223229.CrossRefGoogle Scholar
Elliott, P. (2016) Jahnsite-(CaFeMg), a new mineral from Tom's quarry, South Australia: description and crystal structure. European Journal of Mineralogy, 28, 991996.CrossRefGoogle Scholar
Grice, J.D., Dunn, P.J. and Ramik, R.A. (1990) Jahnsite-(CaMnMn), a new member of the whiteite group from Mangualde, Beira, Portugal. American Mineralogist, 75, 401404.Google Scholar
Grey, I.E., Keck, E., MacRae, C.M., Glenn, A.M., Mumme, W.G., Kampf, A.R. and Cashion, J.D. (2018) Secondary Zn-bearing phosphate minerals associated with alteration of phosphophyllite at Hagendorf-Süd, Bavaria. European Journal of Mineralogy, 30, 10071020.CrossRefGoogle Scholar
Grey, I.E., Keck, E., Kampf, A.R., MacRae, C.M., Cashion, J.D. and Glenn, M. (2019a) Jahnsite-(CaMnZn), IMA 2019-073. CNMNC Newsletter No. 52. Mineralogical Magazine, 83, 887893.Google Scholar
Grey, I.E., Mumme, W.G., Downes, P.J., Grguric, B.A. and Gable, R.W. (2019b) Segelerite from the Mount Deverell variscite deposit, Western Australia. Hydrogen bonding and relationship to jahnsite. European Journal of Mineralogy, 31, 465471.Google Scholar
Hochleitner, R. and Fehr, K.T. (2010) The keckite problem and its bearing on the crystal chemistry of the jahnsite group: Mössbauer and electron-microprobe studies. The Canadian Mineralogist, 48, 14451453.Google Scholar
Kampf, A.R., Steele, I.M. and Loomis, T.A. (2008) Jahnsite-(NaFeMg), a new mineral from the Tip Top mine, Custer County, South Dakota: Description and crystal structure. American Mineralogist, 93, 940945.CrossRefGoogle Scholar
Kampf, A.R., Alves, P., Kasatkin, A. and Skoda, R. (2019) Jahnsite-(MnMnZn), a new jahnsite-group mineral, and formal approval of the jahnsite group. European Journal of Mineralogy, 31, 167172.CrossRefGoogle Scholar
Lagarec, K. and Rancourt, D.G. (1998) Recoil – Mössbauer Spectral Analysis Software for Windows. Mössbauer Group, Physics Department, University of Ottawa, Canada.Google Scholar
Mandarino, J.A. (2007) The Gladstone–Dale compatibility of minerals and its use for selecting mineral species for further study. The Canadian Mineralogist, 45, 13071324.Google Scholar
Moore, P.B. and Araki, T. (1974) Jahnsite, CaMn2+Mg2(H2O)8Fe3+2(OH)2[PO4]4: A novel stereoisomerism of ligands about octahedral corner-chains. American Mineralogist, 59, 964973.Google Scholar
Moore, P.B. and Ito, J. (1978) I. Whiteite, a new species, and a proposed nomenclature for the jahnsite-whiteite complex series, II. New data on xanthoxenite. III. Salmonsite discredited. Mineralogical Magazine, 42, 309323.CrossRefGoogle Scholar
Mücke, A. (1981) The paragenesis of the phosphate minerals of the Hagendorf pegmatite – a general view: Chemie der Erde, 40, 217234.Google Scholar
Rodriguez-Carvajal, J. (1990) FULLPROF: A Program for Rietveld Refinement and Pattern Matching Analysis. Satellite meeting on powder diffraction of the XV Congress of the IUCr, Toulouse, France, 1990.Google Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751767.CrossRefGoogle Scholar
Vignola, P., Hatert, F., Rotiroti, N., Nestola, F., Risplendente, A. and Vanini, F. (2019a) Jahnsite-(MnMnFe), Mn2+Mn2+Fe2+2Fe3+2(PO4)4(OH)2⋅8H2O, a new phosphate mineral from the Malpensata pegmatite, Olgiasca, Colico municipality, Lecco province, Italy. The Canadian Mineralogist, 57, 225233.CrossRefGoogle Scholar
Vignola, P., Hatert, F., Baijot, M., Rotiroti, N., Risplendente, A. and Varvello, S. (2019b) Jahnsite-(MnMnMg), Mn2+Mn2+Mg2+2Fe3+2(PO4)4(OH)2⋅8H2O, a new phosphate mineral species from Sapucaia pegmatite, Sapucaia do Norte, Galiléia, Minas Gerais, Brazil. The Canadian Mineralogist, 57, 363370.CrossRefGoogle Scholar