Iron

Iron is a chemical element with symbol Fe (from Latin ferrum) and atomic number 26. It is a metal, that belongs to the first transition series and group 8 of the periodic table. It is by mass the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust.

Pure iron is very rare on the Earth's crust, basically being limited to meteorites. Iron ores are quite abundant, but extracting usable metal from them requires kilns or furnaces capable of reaching 1500 °C or higher, about 500 °C higher than what is enough to smelt copper. Humans started to dominate that process in Europe and Asia only about 2000 BCE, and iron began to displace copper alloys for tools and weapons, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron Age.

Iron in The War Between the Provinces
The dark haired colonists in Detina brought iron weapons from the mother kingdom. The native blonds lacked iron, having only tools of bronze. In the colonial wars, the dark-hairs triumphed partly for this reason, and partly for having stronger gods.