Superconductivity in diamond
  We report the discovery of superconductivity in boron-doped diamond synthesized at high pressure (8-9 GPa) and temperature (2,500-2,800 K). Electrical resistivity, magnetic susceptibility, specific heat, and field-dependent resistance measurements show that boron-doped diamond is a bulk, type-II superconductor below the superconducting transition temperature Tc=4 K; superconductivity survives in a magnetic field up to Hc2(0)=3.5 T. The discovery of superconductivity in diamond-structured carbon suggests that Si and Ge, which also form in the diamond structure, may similarly exhibit superconductivity under the appropriate conditions. 
E. A. Ekimov, V. A. Sidorov, E. D. Bauer, N. N. Mel'nik, N. J. Curro,   J. D. Thompson, and S. M. Stishov