What is Patina

Hi all,
Just lost an ebay auction on a beautiful W&B (dirty dirty dirty snipers :nono: ).

One thing was in the description that I wasn't sure about. What is Patina?

I did a quick search through the forums and found that it can be removed with sand paper, but not what it is. :thinking:

Any takers?

Tarnish... it comes off with metal polish. If it doesn't come off with polish, it ain't patina, it's rust.

Surface oxidation.

I second both descriptions. Just want to add that you don't know how deep the oxidation until you remove it and then you may find that you have quite noticeable pitting. Until it is removed it looks like an even surface.

I've bought a couple of blades with "light patina" that needed a good amount of work with the 120grit flap-wheel. The absolute winner was the Torrey that ended up being aesthetically useless. Gave it away as a honing practice piece.

Cool, thanks for that :tu