Carrollite

These samples of carrollite are displayed in the Smithsonian Museum of Natural History. Carrollite is a sulfide mineral of copper, cobalt and nickel with the composition Cu(Co,Ni)₂S₄ . The sample at left is about 3x8 cm and the right sample is about 3x4 cm. They are from Kamboye, Shaba, D. R. Congo. The carrollite is formed with quartz.