Room-temperature sulfidation of 100 nm-sized copper nanoparticles with powderous elemental sulfur in chloroform results in fast formation of irregular nanostructured CuS (covellite) particles containing nanoplates. These were characterized by Raman and UV-Vis spectroscopy, X-ray diffraction and scanning and transmission electron microscopy. The reaction is judged to occur via breakdown of the Cu nanoparticles by reactively interacting sulfur solutes and via growth of the CuS nanobodies involving interdiffusion and redox reaction of S and Cu atoms.