Why don't you do a google search? I think the sandpaper would scratch the glass up so bad you would never be able to polish the scratches out again.
One time I had a special half round piece of glass made for a special job. I had made the frame myself by laminating thin plywood to that shape. They hadn't cut the glass exactly right and I had a little trouble fitting it to my frame. So I though to sand the edges a little.
Regrettably I must have touched more than just the edge because afterwards there were some scratches visible. I used everything including special glass polishes and a power buffer and never got them out.
