Disclosed herein are lamps which comprises a discharge vessel comprised of a ceramic material; at least one electrode extending into the discharge vessel; an ionizable fill sealed within the discharge vessel, the fill comprising Hg, a buffer gas component, and a halide component comprising at least an alkali metal halide component and a rare earth halide component; a source of available oxygen; and a metallic component. The discharge vessel defines an interior space which comprises available oxygen during lamp operation conditions. Also disclosed herein are associated methods for making and using such lamps. Disclosed advantages may include mitigating some of the deleterious effects of highly electronegative species, enhanced lumens, and balancing the level of available oxygen for wall cleaning.