My silver item has changed color, what do I do?

My silver item has changed color, what do I do?

Silver goes through an oxidation process as soon as it comes in contact with air, which darkens it.
Some of that dark oxidation can end up on the skin.

Many companies put lacquer on their silver jewelry to prevent this, and to keep the shine.
Since we work with historical jewelry, we do not practice this. We want the metal to "live" as it did back then.