A quartz iodine lamp also called tungsten-halogen lamp, the halogen lamp or the quartz-halogen lamp is an incandescent lamp wherein a tungsten filament is sealed into a small transparent envelope filled with a halogen gas such as iodine or bromine. The halogen lamp can operate its filament at a higher temperature than in a standard vacuum or inert-gas filled lamp, without loss of operating life. This gives it a slightly higher efficiency than standard incandescent lamps