Metallic carrollite crystal in pyrophyllite with quartz. Shaba, Zaire. Crystal is about 1 cm across. (Photo by W. Cordua.)
Formula: Cu(Co,Ni)2S4 Isometric
Description: Carrollite is gray metallic sulfide mineral containing copper, cobalt and nickel formed in hydrothermal deposits.
RUSK COUNTY: Carrollite has been tentatively identified as silvery black crystals on dolomite from the carbonate zone of the Flambeau Copper Mine, near Ladysmith. (Buchholz, personal communication)
Properties of minerals 