Buttons Found on 1930's site

[ClayDigger]

I found the the two dark metal buttons stuck together. The silverish button came through loud and clear with a high tone, but am unsure of the makeup of any of them. found on a 1930's site that I found recent relics at. Any help would be appreciated.

[vayank54]

I think they date early to mid 1900's. the silverish one is probably aluminum. the other two might not be metal at all but metalized plastic. It's a hard plastic with a thin copper like coating. The are very light weight and usually the coating is starting to peel away from the plastic.