Vehicle headlamp

2 3 Metal halide lamp suitable as projection lamp, for instance as a vehicle headlamp comprising a discharge vessel surrounded by an outer envelope with clearance and having a ceramic wall which encloses a discharge space filled with a filling comprising an inert gas, such as xenon (Xe), and an ionizable salt, wherein in said discharge space two electrodes are arranged whose tips have a mutual interspacing so as to define a discharge path between them, with the special feature that said ionizable salt comprises NaI, TlI, CaIand XIwherein X is selected from the group comprising rare earth metals.