A method for polishing of a ceramic arc tube for use in a HID lamp in order to decrease surface scatter and increase in-line transmission of light through the arc tube. In accordance with one embodiment of the invention, processes are described by which both the inner surface and outer surface of a ceramic arc tube may be polished concurrently. In one embodiment, the ceramic arc tube may be immersed in an abrasive slurry and impacted with the abrasive slurry through generation of a turbulence in the abrasive slurry, for example. In one embodiment, the turbulence may be generated by ultrasonic cavitation within the slurry or by a magnetically induced rotational flow within the slurry.