Prehistoric men used to fish and hunt to stay alive. At the beggining spearheads were made using bones or stones. It took a long time to discover metals...
Iron was discovered in the prehistory. Probably, someone found out that there were some stones that, once you put them into the bonfire, they became a pasty red thing, which shape could be easily modified if you hit it with a hammer. They used it to made weapons and decorative objects.
We've got proofs that Sumerians and Egyptians were been using iron since 4000 b.C; and between 2000 and 3000 b.C some civilizations used iron as a ritual object, and it had more value than gold. Some of this iron came from meteorites.
Iron slowly started to replace bronze, and during this process carbonization was found out. Carbonization consists of mixing carbon and iron to create a new etal with better propierties (steel). It was the decisive point to make iron/steel could get to replace bronze before it started expanding all over the world.
During the following cenuries, people used different ways to work woth iron, like the "Farga catalana" or the high oven, but it wasn't untill the end of the XVIII century that iron and steel started been used to build bridges and buildings. Nowadays, steel is the most used material because of its great propieries.
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