Yes PKv is right, silver is silver.
With that written, in the beginning of a SHTF scenario, the coin of the realm has more value during bargaining. To trade for 1-gallon of gas for a 1 oz. American Eagle vs. an Australian Kangaroo, the AE wins every time with the uneducated PM trader.
That is why I am a proponent of junk, pre '64 silver coins. It is recognizable as the coin of the realm, and has 90% value.
I own no PM's. They were lost in the ocean during Hurricane Sandy.