Necromancy: By some it is considered as nefarious black arts and by others a vault of opportunities, the very key to the secrets of life. A substantial part of the necromancer’s practice is devoted to undeath; a state in which one is neither alive nor dead. Unbeknownst to the general populace there are three ways in which undeath can provoked, and the curse of unlife bestowed upon the recipient.
This is a system for balancing magic based on two negative aspects: A) Magic creates “noise” that those sensitive to power will notice and B)Magic is channeled through rifts to other parts of reality OR other dimensions/planes/what have you and those rifts can get out of control…
Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine. ... meeting a party of blue-skinned humans armed with pick-axes etc. Strange disease? Demon offspring? Curse? If they meet only one ex-worker, they will very carefully listen to any stories he says, no matter if drunken or insane, or just makes up to get a beer.