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The chemistry and structure of redledgeite

Published online by Cambridge University Press:  05 July 2018

B. M. Gatehouse ,
G. C. Jones ,
A. Pring  and
R. F. Symes
B. M. Gatehouse
Affiliation:
Department of Chemistry, Monash University, Clayton, Vic. 3168, Australia
G. C. Jones
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London, SW7 5BD, England
A. Pring
Affiliation:
South Australian Museum, North Terrace, Adelaide, SA 5000, Australia
R. F. Symes
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London, SW7 5BD, England
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Abstract

Two distinct habits of redledgeite are described: small black bipyramidal crystals and yellow-green fibres. The mineral is a Ba-Cr-Ti oxide rather than a Mg-Cr-Ti oxide as previously supposed. Electron microprobe analysis gave Ba1.10(Cr1.82Ti5.95 Fe0.10V0.08)Σ7.95O16 and Ba1.27(Cr2.48Ti5.49Fe0.02)Σ7.99 O16 for the black and yellow-green forms respectively. The mineral is a monoclinic hollandite-type phase, space group I2/m, with a = 10.129(2); b = 2.959(1); c = 10.135(2) Å; β = 90.05(11)° and Z = 1; calculated density for the black form is 4.413 g cm−3. The crystal structure was refined to R 6.3%, Rw 7.4% using 1017 reflections with F > 3σ(F) from a set of 1062 unique reflections. Electron diffraction studies revealed weak superlattice reflections, with a period of 2.24b due to tunnel cation ordering.

Keywords

redledgeitecrystal chemistryhollandite-type structureRed Ledge gold mineCalifornia
Type
Crystal structure studies
Information
Mineralogical Magazine , Volume 50 , Issue 358 , December 1986 , pp. 709 - 715
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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References

Bursill, L.A., and Grzinic, G. (1980) Ada Crystallogr. B36, 2902.CrossRefGoogle Scholar
Byström, A., and Byström, A.M. (1950. Ibid. 3, 146.CrossRefGoogle Scholar
Cadee, M.C. and Verschoor, G.C. (1978. Ibid. B34, 3554.CrossRefGoogle Scholar
Cromer, D.T., and Mann, J.B. (1968. Ibid. A34, 321.CrossRefGoogle Scholar
Fallon, G.D., and Gatehouse, B.M. (1980) J. Solid State Chem.34,1193.Google Scholar
Gordon, S.G., and Shannon, E.V. (1928) Am. Mineral., 13, 69.Google Scholar
Post, J.E., Von Dreele, R.B., and Buseck, P.R. (1982) Ada Crystallogr, B38, 1056.CrossRefGoogle Scholar
Pring, A., and Jefferson, D.J. (1983) Mineral. Mag. 47, 65.CrossRefGoogle Scholar
Scott, J.D., and Peatfield, G.R. (1986) Can. Mineral., 24, 55.Google Scholar
Shannon, R.D., and Prewitt, C.T. (1969) Ada Crystallogr. B25, 925.CrossRefGoogle Scholar
Sheldrick, G.M. (1976) SHELX76. Program for crystal structure determination. Cambridge University, England.Google Scholar
Sinclair, W., and McLaughlin, G.M. (1982) Acta Crystal logr, B38, 245.CrossRefGoogle Scholar
Sinclair, W., and McLaughlin, G.M. Ringwood, A.E. (1980. Ibid. B38, 2913.CrossRefGoogle Scholar
Strunz, M. (1961) Neues Jahrb. Mineral. Mh.107.Google Scholar
Strunz, M.(1963. Ibid. 116.Google Scholar
Szymanski, J.T. (1986) Can. Mineral., 24, 67.Google Scholar
Zhuravkeva, L.N., Yarkina, K.V., and Ryabera, E.G. (1978) Dokl. Akad. Nauk SSSR, 239, 435.Google Scholar