If it truly is an event of cataclysmic proportion, gold coins won't be worth their weight.

If it's simply a really bad economic crash, then eventually the economy will recover to the point of not needing to trade in such things as precious metals which can't be eaten, burned for fuel or much of anything really when it comes right down to it. I suppose one could smelt down the metal and make some extra conductive electrical fittings with both gold and silver but I don't know that having really nice speaker connections will be at the top of anyone's real needs list...

If you can find someone to take "precious" metals in trade for things like food in a post cataclysmic event, more power to you.They can use the silver to make bullets to kill the werewolves or something...are zombies allergic to silver?

John E