Oxidation
Oxidation results when metal combines with oxygen and produces an oxide or antique finish. This is not tarnish but a coating of oxide such as what results when sterling silver (a copper and silver alloy) is heated and a copper oxide coats the object.
Oxidation
A Double Sided Silver Lorgnette with Extravagant Open Pierced Work and Plentiful French Style Scrolling. The Silver is Imbued with Natural Black Oxidation Amassed Over Ten Decades of Gentle Aging.