Iron Metallic Chemical Element
Iron | About 5% of Earth's Crust
Iron is a metallic chemical element which makes up about 5% of Earth's crust.
This lustrous workable metal is widely used in industry. Although naturally magnetic, iron can be demagnetized. Its magnetic properties have helped with the study of the history of Earth. The ancient particles in rocks that aligned in different directions over thousands of years reflect changes in Earth's magnetic field.
Pure iron is a soft metal that conducts heat and electricity. It's mostly alloyed with other chemical elements particularly carbon to improve strength. It reacts to moisture in the air by forming an oxide known as rust.
Iron is essential for animal and human health and is also necessary for the health of plants. The vast majority of iron in our bodies is in our blood. Iron-rich blood cells carry oxygen around the body from our lungs. The iron gives blood its colour.
The red orange and yellow colours that can be seen in some soil and rocks is mostly caused by iron oxides. The red dust on Mars is also caused by iron oxides.
The inner core of the Earth is believed to be a solid iron-nickel alloy. Meteorites of iron and nickel are believed to be some of the earliest materials that formed after the formation of the universe.
In industry almost all iron ore is used to make steel. One of the principal ores of iron is hematite.