How to get rid of marks

[noddy]

I've been using a bumper on my iPhone and I took it off last week. I now have what looks like a highly polished dot on the side on the aluminium. I suspect it's been rubbing on the bumper. Will it just oxidise eventually and fade or am I stuck with it?

 

[chunky]

It's been discussed before that the plastic on a bumper can after time cause a polished mark from the rubbing during use and dirt that accumulates under it.

One way to help with this is fitting on lucky labs decal strips or just don't use a bumper.