Try scrapping it on the wall and if it scrapes, you'll know its not real silver. Silver are strongly connected to scrape off. You can still deep it into a freezer and see how fast it takes the cold. Silver is a good conductor of heat.
Erm well the guy above, that work pretty well but can damage it. I would go to a jewelry store or a pawn shop that sells jewels to get it checked out. They'll tell you if it's real or not Hope this helped- Video Maker and Gamer??