Renierite is a very rare germanium sulfosalt species, that also contains copper, zinc, arsenic and iron. This old-time, slabbed and polished specimen is from the Type Locality in the Democratic Republic of Congo - the Kipushi Mine (Prince Leopold Mine). The lustrous, massive, metallic-gray upper portion of the piece is the renierite and it rests on a matrix of chalcopyrite and tennantite. This material probably dates to the 1950s or 1960s and is accompanied by an older Burminco label. Heavy for its size at 41 grams. Ex. Mullane Collection.