Ore

is a common resource

Obtaining
can be:
 * Found in loot on a Cave structure
 * Collected by Mining any type of Ore Vein.

Usages
is smelted to become an Ingot. 3 of the same type of make 1 Ingot

Rarity
Starting from most common to rarest:
 * Copper
 * Gold
 * Iron
 * Silver
 * Mythril