Linnaeite

Linnaeite was first reported from Tsumeb by Geier (1973/74), in chalcopyrite-bornite ore collected on 20 Level. Bartelke (1976) reported that grains of linnaeite "… are just visible to the naked eye as metallic, steel-grey inclusions"; for all practical purposes, however, linnaeite is only visible in polished section.

Pinch and Wilson (1977) stated that linnaeite "Forms metallic, steel-gray inclusions and octahedrons visible only through the microscope".

Cobalt is a relatively scarce element at Tsumeb, averaging 5 ppm in run-of-mill ore over a ten-year period between 1964 and 1974. According to Lombaard et al. (1986) the main carriers of cobalt in the hypogene assemblage were pyrite, carrollite and linnaeite. They considered linnaeite, however, as "extremely rare".

Hughes (1987, citing unpublished TCL reports) cautions that Geier’s identification of linnaeite was based only on its optical properties, and that he could have mistaken it for nickel-bearing carrollite.

In the absence of analytical verification, questionable status is retained for linnaeite at Tsumeb.