Publication Type:

Book Chapter

Authors:

McDonald, A. M.; Cabri, L. J.; Stanley, C. J.; Rudashevsky, N. S.; Poirier, G.; Mungall, J. E.; Ross, K. C.; Durham, B. R.; Rudashevsky, V. N.

Source:

S (super 3) ; sulfides, structures, and synchrotron light; a tribute to Michael E. Fleet, Mineralogical Association of Canada, Ottawa, ON, Canada, Volume 43, Part 5, p.1735-1744 (2005)

ISBN:

0008-4476

Keywords:

Canada, Canadian Shield, cape smith fold belt, chemical composition, Churchill Province, eastern canada, electron probe data, instruments, metals, new minerals, North America, optical properties, Palladium, physical properties, platinum group, platinum minerals, quebec, sample preparation, SEM data, Separation, stibnite, sulfides, techniques, ungava

Abstract:

Ungavaite occurs associated with monoclinic pyrrhotite, pentlandite, chalcopyrite, galena, sphalerite, cobaltite, a chlorite-group mineral and magnetite in the Mesamax Northwest deposit, Cape Smith fold belt, Ungava region, northern Quebec. Associated precious-metal minerals include another new mineral species, naldrettite (Pd (sub 2) Sb), sperrylite, sudburyite, michenerite, Au-Ag alloy, altaite, petzite and hessite. Ungavaite ccurs as rare anhedral grains with inclusions of Au-Ag alloy, or with attached chalcopyrite and a chlorite-group mineral. Grains vary in size from approximately 36 to 116 mu m; they are distinctly anisotropic, and appear bright creamy white in association with pentlandite, pyrrhotite and chalcopyrite; reflectance approximately 58% (46 in oil); D (sub calc) 7.264 g/cm (super 3) . EPMA gave Pd 54.53, Fe 0.13, Te 0.09, Sb 44.59, Bi 0.42, Hg 0.19, As 0.20, = 100.15, leading to the idealized formula Pd (sub 4) Sb (sub 3) ; it is the Pd-dominant analogue of genkinite. Indexed XRD powder data are tabulated; strongest lines 2.268(100), 3.008(90), 1.9404(60), 2.147(30), 1.2043(30), 1.2002(30) Aa; a 7.7388, c 24.145 Aa, V 1446.02 Aa (super 3) , Z = 8, possible space groups P4 (sub 1) 2 (sub 1) 2, P4 (sub 1) 22, P4 (sub 3) 2 (sub 1) 2, (sub ) P4 (sub 2) 2 (sub 1) 2 or P4 (sub 2) 22. Ungavaite formed in a narrow (Pd + Sb)-rich zone separating massive and disseminated sulphides; it is probably a product of the hydrothermal remobilization of Pd (and possibly Sb) from the pre-existing massive sulphides and may have developed at a temperature of below 400 degrees C, possibly via a solid-state order-disorder transformation. The name is for the region.

Notes:

GeoRef, Copyright 2018, American Geological Institute.<br/>2006-039703<br/>Mesamax Northwest Deposit<br/>ungavaite