Iron is a metallic chemical element which has been utilized by humans for centuries. The metal has played such an important role in human history that an entire era, the Iron Age, is named for it. It has numerous industrial uses, with the metal often appearing in alloys, and it is also considered a trace element which is vital for human health. You probably interact with iron in numerous alloys and forms every day, since the element is a ubiquitous part of life on Earth.
Pure iron is a silvery white, very lustrous metal. It is extremely malleable and ductile, which is one of the reasons it has been used by humans for so long, since it does not require complex technology to be worked. The metal is identified with the symbol Fe on the periodic table of elements, and it has the atomic number 26. Alloys which contain iron or act like it are called ferrous metals, in a reference to the Latin ferrum.
This metallic element is generally magnetic, although it can also be demagnetized. Because iron will remain magnetized even after a magnetic object is removed from its vicinity, it is considered ferromagnetic. Several metals demonstrate this property, and they have many useful qualities; not least as refrigerator magnets. The magnetic properties of this metal have been a useful tool in studying the history of the Earth, as ancient particles in rock have aligned in different directions over thousands of years, reflecting changes in the magnetic field of the Earth.
On Earth, iron does not appear in a pure form; it can be found in compounds with other rocks known as ores. These ores need to be treated in furnaces to extract the usable metal and other materials. Occasionally, it appears in meteorites and other objects which originate from space; many early humans had deep superstitions about “star iron,” since it can from the heavens rather than being taken from the Earth. Iron smelting is a major industry, since the metal is used in so many objects.
Humans and many other living organisms require this element for well being. Dietary iron can be found in red meat, dark leafy greens, dried fruit, beans, nuts, and seeds. A deficiency can lead to anemia, a serious medical condition. Too much can cause diarrhea, stomach cramps, and other symptoms; iron poisoning in children is an issue in some regions, usually because children eat supplement pills intended for adults.