Iron has been known since ancient times. The first iron used by humans probably came from meteorites.
Most of the objects that fall to earth from space are stony, but a small proportion, like the one pictured, are «iron meteorites» with iron contents of more than 90 percent.
Iron corrodes easily, so iron artifacts from ancient times are much rarer than objects made of silver or gold. This makes it more difficult to trace the history of iron than less reactive metals.
Artifacts made from meteorite iron have been found dating to around 5,000 BC (and thus approximately 7,000 years old), for example iron beads in tombs in Egypt.
In Mesopotamia (Iraq) there is evidence that people were smelting iron around 5000 BC
Cast iron artifacts dating to around 3000 BC have been found in Egypt and Mesopotamia.
In those days, iron was a ceremonial metal; it was too expensive to be used in everyday life. Assyrian scriptures tell us that iron was eight times more valuable than gold.
The Iron Age began around 1300-1200 BC, when iron became cheap enough to replace bronze.
iron discovery
carbon
The addition of carbon to iron to make steel was probably accidental at first: a fusion of molten iron and carbon from the foundry fire. This probably happened around 1000 BC.
Until this happened there was little technological reason for the Bronze Age to give way to the Iron Age; techniques for improving iron by adding carbon (to make steel) and cold working were necessary before iron was wholly preferred to bronze.
Iron was commonly used in Roman times. In the first century, Pliny the Elder said: «It is with the help of iron that we build houses, break stones and carry out so many other useful functions in life.»
The origin of the chemical symbol Fe comes from the Latin word ‘ferrum’, which means iron. The word iron itself comes from ‘iren’ in Anglo-Saxon.
Interesting facts about iron
One third of the Earth’s mass is believed to be iron, most of which is found deep within the planet, in the core.
Earth has enough iron to form three new planets, each with the same mass as Mars.
The circulation of liquid iron deep within the earth is believed to create the electrical currents that create our planet’s magnetic field.
Iron is essential for the development of the human brain. Iron deficiency in children leads, among other problems, to a limited ability to learn.
In ancient times, people did not know how abundant iron was on Earth. Their only source of metallic iron was meteorites. From the Assyrian scriptures we learn that iron was eight times more valuable than gold.
In addition to its rarity, iron may also have been highly desirable because, coming from heaven, it was thought to be a gift from the gods: the ancient Egyptians called it ‘ba-ne-pe’, meaning ‘metal from heaven’.
The connection with heaven is reinforced by the Pyramid Texts which translate, for example, into: «my bones are iron and my limbs are the imperishable stars».
Iron was the first magnetic metal discovered. Ancient navigators used Lodestones because they could be used as compassespointing to the north magnetic pole.
This was described by the ancient Greek philosopher Thales of Miletus in 600 BC. Lodestones are made of magnetite, which is a naturally occurring iron oxide. Magnetite’s formula is FeO.Fe 2 O 3 .
Some animals have a sixth sense: the magnetic sense. Magnetite has been found in a wide range of animals, including honey bees, homing pigeons, and dolphins.
These animals are sensitive to the earth’s magnetic field, which aids their ability to navigate.
The Hoba meteorite in Namibia is the largest piece of iron in the world, weighing more than 60 tons.
It is made of 82 – 83% iron, 16 – 17% nickel, about 1% cobalt, and very small traces of other elements. The Hoba meteorite is the largest meteorite ever found.
ferromagnetism
Iron is ferromagnetic. Ferromagnetism is the strongest type of magnetism. Other common ferromagnetic metals are nickel and cobalt.
Very powerful magnets can be made using iron, nickel or cobalt in association with rare earth metals. NIB (Neodymium Iron Boron) magnets were invented in the early 1980s.
They are an alloy in the proportions Nd 2 Fe 14 B. They are used in computers, cell phones, medical equipment, toys, motors, wind turbines, and audio systems.
History and properties of iron
Archaeologists estimate that people have been using iron for more than 5,000 years. In fact, it turns out that some of the oldest iron known to humans literally fell out of the sky.
In a 2013 study published in the Journal of Archeological Science, researchers examined ancient Egyptian iron beads dating to around 3200 BC and found they were made from iron meteorites.
The Old Testament in the Bible also mentions iron several times, according to the Los Alamos National Laboratory.
Iron is obtained mainly from hematite and magnetite ores. In smaller grades, it can also be obtained from the minerals taconite, limonite, and siderite.
The atoms
Iron has four different allotropic forms, which means that it has four different structural forms in which the atoms they come together in different patterns, according to the Los Alamos National Laboratory. Those shapes are called ferrites, known as alpha (which is magnetic), beta, gamma, and omega.
Iron is an important nutrient in our diet. Iron deficiency, the most common nutritional deficiency, can cause anemia and fatigue that impairs the ability to perform physical work in adults.
It can also affect memory and other mental functions in adolescents, according to the Centers for Disease Control and Prevention. Women who are iron deficient during pregnancy are at increased risk of having small and premature babies, the CDC warns.
Two types
There are two types of dietary iron: heme iron and non-heme iron. Heme iron, which is the most easily absorbed type of iron, is found in meat, fish, and poultry, while non-heme iron, which is also absorbed but to a lesser extent than heme iron, is found in in both plant foods (such as spinach, kale and broccoli) and meat, according to the American Red Cross.
People absorb up to 30 percent of heme iron, compared with 2 to 10 percent of nonheme iron, ARC reports, adding that vitamin C-rich foods like tomatoes or citrus fruits can help people who don’t absorb iron absorb.
Who knows?
Blood is red due to the interaction between iron and oxygen, according to the University of California, Santa Barbara . Blood appears red because of the way the chemical bonds between the two elements reflect light.
Pure iron is really soft and malleable, according to the University of Denver.
In 2007, researchers discovered a huge cloud of iron-rich water emanating from hydrothermal vents in the southern Atlantic Ocean.
Iron is necessary for the growth of phytoplankton, tiny bacteria marine plants that use carbon dioxide from the atmosphere to fuel the photosynthesis.
Some researchers have argued that fertilizing the oceans with extra iron could help absorb excess carbon dioxide.
However, a study published online in November 2010 in the Proceedings of the National Academy of Sciences found that this might not be a good idea, as all this extra iron could actually trigger the growth of contributing toxin-producing algae. to the contamination of marine wildlife resources.
meteorites
About 90 percent of all metal refined today is iron, according to the Royal Society of Chemistry.
Iron is a crucial component of a class of meteorites known as siderites, according to the Los Alamos National Laboratory.
An iron pillar dating to approximately AD 400 still stands today in Delhi, India, according to the Los Alamos National Laboratory.
The pillar is about 23.75 feet (7.25 meters) tall and measures 15.75 inches (40 centimeters) in diameter. Despite being exposed to weather conditions, the pillar has not corroded much due to its unique composition of metals.
Examples of iron-rich foods include meat, such as beef, turkey, chicken, and pork; shellfish, such as shrimp, clams, oysters, and tuna; vegetables, such as spinach, peas, broccoli, sweet potatoes, and green beans; bread and cereals, such as bran cereals, whole wheat bread, and enriched rice; other foods, such as beans, lentils, tomato paste, tofu, and molasses, according to the American Red Cross.
Mars
The surface of Mars is red due to a large amount of iron oxide (rust) on its surface, according to Nature. Mars has more than twice as much iron oxide in its crust as Earth.
Earth’s solid inner and liquid outer cores are composed primarily of iron (about 85 percent and 80 percent by weight, respectively).
The electric current generated by the liquid iron creates the magnetic field that protects the Earth, according to the POT. Iron is also found in the cores of all the planets in the Solar System.
Iron is the heaviest element formed in the cores of stars, according to JPL. Elements heavier than iron can only be created when high-mass stars explode (supernovae).
The Latin name for iron is ferrum, which is the source of its atomic symbol, Fe.
The word iron comes from an Anglo-Saxon word, iren.
The word iron possibly derives from earlier words meaning «sacred metal» because it was used to make the swords used in the Crusades, according to WebElements.
From being a crucial building block of steel to fueling plants to helping carry oxygen in the blood, iron is always busy helping to sustain life on Earth.
It is brittle and hard
Iron is a brittle and hard substance, classified as a metal in Group 8 on the Periodic Table of the Elements.
The most abundant of all metals, its pure form corrodes rapidly on exposure to moist air and high temperatures.
Iron is also the fourth most common element in the Earth’s crust by weight and much of the Earth’s core is thought to be made up of iron. In addition to being commonly found on Earth, it is abundant in the sun and stars, according to the Laboratory…