Once set in motion, electrical current will flow forever in a closed loop of superconducting material.
Superconductivity is also sometimes referred as "macroscopic quantum phenomenon."
The second property of these materials is perfect diamagnetism i.e. that the superconducting material will exclude a magnetic field which is known as the Meissner effect.
Type II Superconductors - which totally exclude low applied magnetic fields, but only partially exclude high applied magnetic fields; their diamagnetism is not perfect but mixed in the presence of high fields. Niobium is an example of an elemental Type II superconductor. YBa2Cu3O7 (YBCO) and Bi2CaSr2Cu2O9 are examples of. High temperature Type II ceramic superconductors.