Kingdom of Naples (Italian states)
½ Ducato - Felipe II
https://en.numista.com/catalogue/pieces123479.html
Though that is not your coin - 34mm
Maybe yours was never a coin, as the loop looks like it always was
part of it so may have been made altogether as a necklace, with that design.
Especially as the loop is at the top of the obverse but way off on the reverse.
This (27mm) is closer to yours, but not the same lettering ...
https://en.numista.com/catalogue/pieces52252.html
The general quality does not look old, and it is not looking like silver either.