Carrollite
![](/Images/godic/202501/03/Carrollite025228.jpg")
![Carrollite from Katanga, specimen 11 × 6 cm](/Images/godic/202501/03/Carrollite5228.jpg")
![Carollite and native copper on calcite](/Images/godic/202501/03/Carollite_and_native_copper5228.jpg")
Carrollite, CuCo2S4, is a sulfide of copper and cobalt, often with substantial substitution of nickel for the metal ions, and a member of the linnaeite group. It is named after the type locality in Carroll County, Maryland, US, at the Patapsco mine, Sykesville.