What polishes glass?
This is going to depend on whether you’re actually removing a scratch or just polishing what seems to be a very dull area. If you are removing a scratch, keep in mind the process is going to work a lot like sanding and finishing. It will require starting with a point that can reduce the appearance of the scratch. Then work into finer accessories from there. You may have to try a couple of items. For example, you may want to try a diamond wheel point. This will tend to create a more etched appearance on the glass. If removing a larger scratch, start with that. Then move to finer items like emery-impregnated points, a felt polishing point with polishing compound on it and finally rubber polishing points.