Where do mineral ores come from?

The core of the planet of Scarterra is the Elemental Plane . Periodically the elemental plane releases new elements into the material plane.
It's normally not that big of a deal if new air or water is created, but it's when minerals force their way into Scarterra that issues arise. Periodically this creates earthquakes or volcanic activity. It also impacts who has access to the wealth of the earth and who does not.
Regulating this is primarily Hallisan's Dominion but the rest of the Nine sometimes choose to poach on Hallisan's domain and interfere with what minerals go where.
That means it's possible to have a self-replenishing mine (nicknamed "a hot mine").  Hallisan preaches about fairness and justice but he is not above playing favorites with mortals (hence why the rest of the Nine often feel morally justified interfering with Hallisan's domain).
A "cold mine" is also called a "normal mine". Cold mines are actually replenished the same way hot mines it's just that the replenishment events are so rare that most mortals have no realistic chance of witnesses one, especially in a predictable manner.
Most self replenishing mines are held by dwarves.  It's a debate whether this is because Hallisan is showing favoritism to dwarves or simply that dwarves are better at finding these sites.

Type

Metaphysical, Elemental