Fake Silver Coin Candle test.
It is my test but it works based on silvers high thermal conductivity compared to other metals. From a coin at room temperature, hold the edge of a coin on the top of the yellow candle flame, it should take around 9 to 15 seconds for real silver before it is too hot to hold. And when the heat comes, it comes fast.
Other metals are way over 20 seconds and up to 35 seconds. If you are worried about damaging the coin, well, it's not going to if it is real silver.