A burnisher can be used to make a polished surface, fix a scratch or move metal in a variety of situations. I use deer antler on wood, high carbon steel on some steels and non ferrous metals, agate is one used in some fields but I don't own. A burnisher can be in a variety of forms and materials but they all are highly polished and harder than the material they intend to move.
Mark
Gesswein sells a nice carbide burnisher very reasonable. Also to repair scratches rub the tool back and forth in the direction of the scratch, not across. Then touch up the area with the origional grit paper or polish. You will be amazed a what can be repaired