Nickel Minerals from Barberton, South Africa: I
American Mineralogist, Volume 58, pages 733-735, 1973 NickelMinerals from Barberton,South Africa: Vl. Liebenbergite,A NickelOlivine SvsneNoA. nn Wnar Nationnl Institute lor Metallurgy, I Yale Road.,Milner Park, I ohannesburg,South Alrica Lnwrs C. ClI.x Il. S. GeologicalSuruey, 345 Middlefield Road, Menlo Park, California 94025 Abstract Liebenbergite, a nickel olivine from the mineral assemblage trevorite-liebenbergite-nickel serpentine-nickel ludwigite-bunsenite-violarite-millerite-gaspeite-nimite, is described mineral- ogically.Ithasa-1.820,P-1.854,7-1.888,ZVa-88",specificgravity-4'60,Mohs hardness- 6 to 6.5, a - 4.727, b - 10.191,c = 5.955A, and Z - 4. X-ray powder data (48 lines) were indexed according to the space grottp Pbnm. The mean chemical composi- tion, calculated from electron microprobe analyses of eight separate liebenbergite grains, gives the mineral formula: (NL eMgoaCoo,sFeo o)Sio "nOn The name is for W. R. Liebenberg, Deputy Director-General of the National Institute for Metallurgy, South Africa. Introduction mission on New Minerals and Mineral Names (rMA). A re-investigationof the trevorite deposit at Bon Accord in the Barberton Mountain Land, South Experimental Methods Africa, led to the discovery of two peculiar but distinct nickel mineral assemblages.Minerals from The refractive indices were determined by the the assemblagewillemseite-nimite-feroan trevorite- conventional liquid immersion method using a reevesite-millerite-violarite-goethitehave been de- sodium lamp as light source.The optical and crystal scribed in earlier papers in this series (de Waal, morphologicalparameters were studiedwith the aid 1969, l97oa, 1970b;de Waal and Viljoen, I97L). of a universal stage.
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