Wrought iron is a confusing term that refers to both a type of metal and a process of formation. More traditionally, it is a variety of iron, with additives that make it twistable with a low corrosion rate. The manufacture of this type of iron has been limited to Europe since 1969, however, because it is very expensive to make and fell out of fashion. More likely, when someone says "wrought iron," they refer to a forged (not truly wrought) iron that resembles the former in appearance, but which is made out of steel. This decorative iron creates reproductions for patio furniture, window screens, and custom fencing.
Authentic wrought iron differs from steel in that it is impregnated with tiny slivers of iron silicate known as "slag." When distributed as fibers, the slag changes the chemical properties of the iron enough to create a new and beneficial metal. This metal is valued for its strength under tensile pressure, resistance to corrosion, malleability, and how well it keeps a finish. Most metals, when corroding, exhibit ugly patches of discolored rust. This form of iron distributes the rust into a dappled coppery or brownish finish that often appeals to people's sense of age.
Antique examples of this ironwork can still be seen on window grates, balconies, doors, and other architectural elements from as far back as the Romans. This ancient, royal decor from before the 18th century was made out of iron created in a charcoal fire. Not until "puddled" iron was possible through mass production did the metal become popular among common people. In the 21st century, Britain's blacksmiths are experiencing a renaissance with supplies from scrap metal.
In the design world, "wrought iron" increasingly refers to a style of metalwork that hearkens back to the heyday of scrolls and curlicues from the Iron Age through Medieval times and into the Protestant Reformation. These ornamental items are distinguished by their twists and turns that give them an attractive shape. Inexpensive accessories, such as candleholders, lamps, and plant stands, decorate many contemporary homes. Most of this ironwork is actually cast iron, and can be identified by brittleness and perfect symmetry, since it is made out of a mold.