Encapsulation of metals inside multilayered polyhedral shells of carbon (nanoencapsulates) is described. Many materials, such as metals and metal-carbides, can be encapsulated by the method of present invention, including metals such as lanthanides, transition metals, actinides and alloys. Some of these nanoencapsulate materials exhibit ferromagnetic and paramagnetic properties and have uses in the biomedical field as well as in recording media and composite materials.