[h0ll0wman]

Originally Posted by Ian

Several possibilities. Sometimes the silver is a silver wash over a copper alloy (brass). The yellowing comes through when the silver is dull (i.e., oxidized)--after polishing, the bright silver reflection obscures the underlying yellow of the brass. Sometimes the silver is alloyed with copper which can also give a yellow hue when the silver is dull. Again, polishing (removing the silver oxide) enhances the light reflection from the silver and obscures the alloyed color. Protective coatings, like varnish, are more obvious causes and can be removed easily with solvents. White brass (German silver) is another white metal that can have a yellowish hue.

I would say that your example likely has a copper-silver alloy, such as coin silver (silver 90%, copper 10%), which was fairly common on gunong.

Wow this is very informative. Thank you Ian!