Allow locate-ore to find coal and other inorganics

[myk002]

there's really no reason why it is restricted to the types that the game calls "ores"

[themaster567]

Please, this is so vital. I can't tell you how much time I've wasted trying to find coal and just getting terribly unlucky.

[shadowsong42]

Upvoting this. I need to search for fuel or flux more often than I need to search for metal ore.