Wrought iron is pure iron crystals with thin layers of silicous slag resulting in grainyness simliar to wood. Lack of carbon makes wrought iron unhardenable but very ductile. The grainyness requires special handling in forging, cutting and punching. Wrought was the product of early bloomeries and was the primary ductile form of iron for several millennia. It was last manufactured as "charcoal iron" in Sweden in 1968. It was last manufactured by the Beyer process in the U.S ending in the 1950's.
Wrought iron is also the description of decorative ironwork that is made of any metal including wrought iron, steel, cast iron and aluminium. Wrought iron is also used to describe low carbon steel pipe.
See glossary entry on iron