Ketchup or lemon juice + salt are very good for cleaning up your tarnished copper jewelry, in case you like it all clean and shiny :-). After cleaning it and washing the ketchup or lemon juice off, polish it well with a handy-dandy sunshine polishing cloth...and its as good as new! :-)
And Tammy added in the comments: Worchestershire sauce or vinegar and salt work great too! Thank you Tammy!
9 hours ago