Iron is a chemical element with the symbol Fe. It is a metal in the first transition series. It is by mass the most common element on the earth, forming much of Earth´s outer and inner core.

The core of the Earth is mainly formed by Iron and Nickel. It has been  historically very important, a period of history is called " The Iron Age"..mineral_de_hierro

Iron metal has been used since ancient times, though copper alloys, which have lower melting temperatures, were used even earlier in human history.

Pure iron is soft (softer than aluminium), but is unobtainable by smelting. The  material is significantly hardened & strengthened by impurities, from melting process.