All the previous comments concerning silver are right on. As far as a replay being different?
My first map had the Elder WAAAAAAY far away from the starting island and I died a bunch just trying to get there. I never made it. I used the same character on a new map where the elder ended up being much closer AND there were two large mountains full of silver right outside my base door. So yes, a new map can be a different (and sometimes better) experience. I'm also one of these idiots that enjoys walking around looking at trees and sunsets so maybe i'm a little biased