I'm assuming the reason raw clay is red is because of the iron content, how do you separate it. also is that why bricks are red? and is porcelain just pure clay? one more thing do smelters of iron (how?) also produce steel at their factorys, and if so is that steel also sold as ingots for further processing. one more thing I'm assuming the way you purify steel is thru magnetic induction. can someone show me an example of a machine that makes steel wire tia. fyi I was watching cnbc and suddenly became interested in the manufacture of guitar string!