| Patina |
A sheen or coloration on any surface, either unintended and produced by age or intended and produced by simulation or stimulation, which signifies the object's age; also called aerugo, aes ustum, and verdigris. Typically a thin layer of greens (sometimes reds or blues), usually basic copper sulfate, that forms on copper or copper alloys, such as bronze, as a result of oxidation and corrosion. Metal objects have naturally acquired patinas when long buried in soil or immersed in water. Such naturally formed patinas have come to be greatly prized. There are many formulae for the pickles and chemical treatments of metals which may be employed to encourage the formation of patinas. (pr. pa'te-nah; pah-tee'nah is also used, but many consider it a mispronunciation) |
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