Patination

A loss of minerals from the surface of an artifact which resulted in a color change usually to a lighter side.

Patination

the thin layer of material that forms on a rock surface after weathering that can change its color

Patination

The effects of time on an object and the finish it imparts.
Found on http://www.antiquerestorers.com/Articles/GOLD/GLOSSARY2.html

patination

(from the article `art conservation and restoration`) ...regularly used, as was chemical stripping (which dissolved the mineral alteration products) and electrochemical reduction, which also stripped the ... Patinas on metals are caused by the corrosive action of chemicals. Sculpture that is exposed to different kinds of atmosphere or b...
Found on http://www.britannica.com/eb/a-z/p/28

Patination

The surface appearance (as a coloring or a mellowing) of something grown beautiful through a lengthy passage of time or extended use. The rosy gold surface on early American gold coins is a good example of patination.
Found on http://amhistory.si.edu/coins/glossary.cfm

patination

formation of a film on copper from exposure
Found on http://phrontistery.info/p.html
No exact match found