What is the original source of iron?

Answer 1

From nuclear fusion of stars. The fusion process starts with hydrogen molecules being pulled together by gravity, proceed to form helium when a critical temperature is reached at about 2.5x10^9 oC, then form heavier atoms such as magnesium, oxygen and calcium.

The nucleosynthesis then follows a complex path through Si - Ca - Ti - Fe - Ni - Co- and finally Fe56 which is stable.

With the formation of sufficient heavy elements, the star gains greater density eventually leading to a dwarf star or a supernova, depending on the size of the starting star. [Our Sun is too small to make iron, so we will not go nova that way!]

About 5% of meteorites are of the iron-nickel type, easily recognized by a characteristic crystal pattern revealed by etching.

The core of the Earth is rich in nickel-iron, and it is possible that the break-up of an early planet that gave us the meteor belt, and the iron.

[In early Earth, the oceans were very rich in dissolved iron, and it was the arrival of the algae and photosynthesis that precipitated it out (due to the production of oxygen) as the immense banded-iron beds, which are the source of the major commercial iron deposits today.]

Answer 2

Iron is a naturally occurring element found in the Earth's crust. It can be extracted from iron ore through a process called smelting, where the iron ore is heated with carbon to remove impurities and extract the iron metal. Iron ore deposits are typically found in the form of hematite or magnetite.