The tissue test will help you tell if the coin's surface is silver. It won't say anything about whether it's solid or silver-plated.
What a party pooper The majority of coins will test correctly. If the OP found a silver looking post 1964 Quarter then there are other ways to figure that out.
Sorry, I've been troubleshooting code all day, I'm in full nit-picking mode. I don't find myself reaching for the tissue-paper test that often, but that's because I don't deal with a lot of unfamiliar coin types (and I've got a scale). The few times that I've tried it, it's seemed pretty effective. In particular, I've seen some really glossy stuff plated with other metals that looked silver, but failed the tissue test miserably.
I use a neodymium magnet and a metal detector with a good meter. You could research the coin and use a scale and calipers.
True. Also true, but then neither will anything else, that is a non-destructive test. Weight, even a specific gravity test will not prove the coin has the correct silver composition as both weight and composition can be faked with the proper alloys. As for the magnet and meter - ehhh, I dunno. Probably work most of the time, but I suspect it could probably be beat too. But like I said, I dunno. Joy - about 95% of the time, the tissue test will tell you what you need to know.
Just search the forums here. Plenty of people have posted the same question. The odds of you having one are basically nil. You can get it scanned by an XRF scanner though. "We Buy Gold/Silver" shops should probably have one they may do it for you. Your other option is to send it to a TPG and shell out the money for them to tell you what you've already been told here. It's up to you.
Also, for what it's worth, the tissue test probably won't work for war nickels. That alloy tarnishes to something even darker than a regular nickel.
Right you are, I tissue tested a silver plated coin I have and a 90% silver Franklin Half and they both look the same.