The first iron to be forged and hammered by a human would probably have been chipped from a meteorite.  Not ideal because meteorites often contain a lot of nickel and they are quite rare.  At some pre-historic point we discovered we could break up rock containing iron and by heating it to a very high temperature we could separate the iron which then needed more heating and hammering to rid it of impurities and produce a workable metal.

Today we have electric furnaces that can produce iron which is so pure it can be used in the pharmaceutical industry.  Our pure iron is a minimum 99.8% pure and is the closest material in production today to the best quality charcoal iron and wrought iron of the 18th and 19th Centuries.