Coal Mine

"an in-game description is needed"

Overview
Coal Mine is a common tier dropper the drops coal ro fuel Industrial Mines. Coal ore is worth $0 and cannot have sums of money added to it (like using it on items like cursed ore purifiers, Heavenly Forge, Ore encapsulator, Ore purifier machine or Portable Flamethrower.

Coal Ore has identical properties to all other ores, it can be upgraded and have value added to it, caught on fire, made radioactive, etc. It can be cashed in - however, this is incredibly inefficient.