In basic terms, oxidation is a gain in oxygen that causes a change in the chemical substance of the oxidized material. In jewelry, oxidation is the discoloration or blackening that happens to a piece of jewelry. It is a type of corrosion that damages the surface of the metal. When a piece of jewelry comes in contact with moisture, acids, oil, or, air it can cause oxidation. Sometimes metals are intentionally oxidized to achieve a certain look. Oxidized silver and sterling silver, for example, are favored for their silver or black patina.
