Patinate - To furnish with a patina. / To acquire or become covered with a patina. (http://www.answers.com)

Patina - # A thin greenish layer, usually basic copper sulfate, that forms on copper or copper alloys, such as bronze, as a result of corrosion.
# The sheen on any surface, produced by age and use.

"Patinated silver pendant"
(http://www.anastasiayoung.co.uk/page15.htm)

"Exceptional sideboard or cabinet finished here in patinated silver architectural frame"
(http://www.interiorinternet.com/SIDEBOARDS_F9_FRAMED_SIDEBOA...