Iron
From Cantr II Wiki
An alloy made from iron ore, limestone and some type of fuel (propane, coal or charcoal) in a smelting furnace or primitive smelting furnace.
Can be further processed into steel using a smelting furnace, but not a primitive smelting furnace.
Used for creating essential tools, machinery, and weapons. The lifeblood of any productive town.
Trivia: In the early stages of the game iron was available from the ground in pure form, but as the game was enhanced this was changed to more accurately reflect the process involved.