Patent ID: 8274224

Claim:
A metal halide lamp comprising a ceramic discharge vessel and two electrodes, the discharge vessel enclosing a discharge volume containing an ionizable gas filling comprising at least a metal halide, two current lead-through conductors connected to the respective electrodes, and a seal including a sealing material through which at least one of the current lead-through conductors issues to exterior of the discharge vessel, wherein the sealing material of the seal comprises a ceramic sealing material comprising cerium oxide, aluminum oxide and silicon dioxide as a mixture of oxides and/or one or more mixed oxides, wherein the ionizable filling comprises NaI, TlI, CaI 2 and REI 3 (rare-earth iodide), wherein the filling comprises at least CeI 3 , and wherein the ceramic sealing material comprises 25 to 60 wt. % Ce 2 O 3 , 12 to 64 wt. % Al 2 O 3 and 3 to 50 wt. % SiO 2 .