Cobalt particles have been prepare by chemical reduction of a cobalt salt (CoCl2) by refluxing ethylene glycol. The beauty of a system made of many particles is related to the size distribution and the shape of the particles. In particular, a beautiful particle system is obtained with monodispersed systems and with shapes of regular geometry (e.g., spheres, triangles, rods). The shown cobalt nanoparticle sample seems to satisfy these characteristics.