Among my list of things to attempt with UE4 is to develop a module which marks sites on the terrain where a player has discovered a vein.
I haven't been discussing this with any of the devs as of yet, because I only recently formulated it. Unless UE4 PlaneShift is planned to allow add–ons for the interface in the same way that some other MMOGs do, it would require first exposing that functionality.
I personally think that some veins could be more obvious than others, but I do like the obscurity of most: that way, the whole procedure is rather like exploring and prospecting for lodes. You can also follow other miners to see where they go.
What the devs ought do is to ensure that sites for mining aren't placed haphazardly: they should be clustered in such a way as would make sense if there really was a larger lode underneath the exposed veins.