fog on Buck blade

[loumc]

I bought a older Buck knife online and the blade seems to have a splochy fog like clear discoloration to it, that does not rub off. Otherwise looks unused.
Any idea what this might be? What caused it or how to clean it off.

 

[ohen cepel]

Standard 110 or a mirror polished blade?

I would use Fritz or MAAS polishing compound on it if I bothered me enough. That should clean it up.

 

[loumc]

it's a 120