I just got an answer from Michelle048 at JustAnswer. https://www.justanswer.com/antiques/expert-michelleo48/

“I can tell you that it is a fiddleback salt spoon And coin silver should be about 90% silver. Many people think it is worthless and the same as nickel silver, which nickel silver has 0 silver, but it is not true. They literally melted down coins and I think this is likely little salt spoon to be early to mid 1800s.”