There are ways to test it if you are worried. Trusted online dealers would go out of business overnight if they sold one piece of fake Silver or Gold. Their reputation is all they have.

I usually stack coins, because it's also money, and if someone was counterfeiting it they'd be in big doo doo. Find a reputable broker, buy a small amount to start with, just to be safe.

Once you're happy, fill yer boots.