CoNi₂S₄

This sample of siegenite is displayed in the Smithsonian Museum of Natural History. Siegenite is a sulfide mineral of cobalt and nickel. It has the composition CoNi₂S₄. This sample is about 4x7 cm and is from Ozark lead mine, Sweetwater, Missouri. The sample is described as siegenite with dolomite.

This sample is described as siegenite with galena and dolomite. This sample is about 14x14 cm and is from Sweetwater mine, Reynolds County, Missouri.