Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-26T11:03:30.736Z Has data issue: false hasContentIssue false

Johninnesite, a arsenosilicate from new sodium manganese the Kombat Mine, Namibia

Published online by Cambridge University Press:  05 July 2018

Pete J. Dunn
Affiliation:
Department of Mineral Sciences, Smithsonian Institution, Washington, DC 20560, USA
Donald R. Peacor
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109, USA
Shu-Chun Su
Affiliation:
Department of Geological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
Joseph A. Nelen
Affiliation:
Department of Mineral Sciences, Smithsonian Institution, Washington, DC 20560, USA
Oleg von Knorring
Affiliation:
21 Churchwood Avenue, Leeds LS16 5LF, England

Abstract

Johninnesite, ideally Na2Mg4Mn12As5+2 Si12043(OH)6,, is triclinic, P1 or P1̄, with a = 10.44(2), b = 11.064(6), c = 9.62(1) Å, α = 107.43(7), β = 82.7(1), γ = 111.6(1)°, V = 894(2) Å3, and Z = 1. It occurs as yellow-brown fibrous aggregates, associated with rhodonite, kentrolite, and richterite, from the Kombat Mine in Namibia. Johninnesite has cleavages on {100} and {010}, density of 3.48 (meas.), 3.51 (calc.) g/cm3. It is biaxial negative, with 2Vx = 41.9°, α = 1.6742(4), β = 1.6968(3), γ = 1.6999(3); dispersion r > υ, distinct.

Type
Silicate mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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.)

Footnotes

*

Permanent address: Institute of Geology, Chinese Academy of Sciences, Beijing, People's Republic of China.

References

Bloss, F.D. (1981) The spindle stage: principles and practice. Cambridge University Press, Cambridge, 340 pp.Google Scholar
Innes, J., and Chaplin, R.C. (1985) Ore bodies of the Kombat Mine, South West Africa/Namibia. Mineral Deposits of Southern Africa,Spec. Publ. Geol. Soc. South Africa. C. R. Anhaeusser, ed. (in press).Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV. The compatibility concept and its application. Can. Mineral, 19, 441-50.Google Scholar
von Knorring, O., Sahama, Th. G., and Tornroos, R. (1978) Second find of nambulite. Neues Jahrb. Mineral Mh.346-8.Google Scholar