What is Iron?

What is Iron?

Iron ore in rock form
iron ore on a rocky base

Did you know that iron is a healthy nutrient for our bodies as well as the main ingredient in the manufacture of steel?

Before we venture into the types of iron, let’s first examine its properties. Iron is a mineral with the symbol Fe and atomic number 26. On the periodic table, it belongs to the first transition series, which reflects a change in the inner layer of electrons, but we’ll leave that for the chemists since the chemical compound of this material is beyond the scope of this article; however, if you’d like to learn more about a material’s transition series, click here.

Iron is the most common element on Earth when referenced by mass and is very prominently found in the Earth’s outer and inner cores. It is the fourth most common element in the Earth’s crust, but the process to extract it requires kilns or furnaces capable of reaching a temperature of 2,730 °F or higher.

A Little Bit of Iron History

The Bronze Age (c. 3300–1200 BC) is characterized by the use of bronze as the metal of choice to create art, tools, and weapons and was the first time metals were used for these purposes. Prior to this period, the stone was used as tools and weapons; hence, the Stone Age.

Interestingly enough, the Bronze Age also brought us the first writing systems and the invention of the wheel. Indeed, an intriguing period of creative thought for sure.

Enter Iron

Say goodbye to bronze and hello to iron; hence, the Iron Age, which started around 1200 BC, but before the Iron Age was coined, there are occasions when iron was found to be used much earlier. One of the most ancient iron historical accounts was that of ancient Egyptians where iron beads dating back to 3200 B.C. were found to be made from meteorites as iron is abundant in outer space also.

Iron for Nutrition

OK so iron is a mineral rock, but it is an important nutrient for our bodies as well. If you have an iron deficiency, you can possibly acquire anemia and also fatigue that affects the ability to perform physical work in adults.

So how much iron do you need on a daily basis? For most people, an adequate amount of iron is consumed daily via the foods that we eat, but to determine your specific iron needs you can see a chart and information here. One person told us that he eats yogurt and raisins every day. Raisins contain a certain amount of iron. 

Red Blood Cells
“Red blood cells” by rpongsaj is licensed under CC BY 2.0

Do you know why our blood is red?  It is because there is an interaction between iron and oxygen within the blood creating a red color. Learn more about red blood cells and iron here.

To be sure you have enough iron, check with your doctor to confirm you are not deficient.

Iron for Infrastructure

Once we enter the 19th century, we come upon new uses for iron besides artifacts and weapons. It was discovered that this mineral can be used for building purposes and with the advent of the industrial revolution, where items were being mass-produced, the manufacture of iron became very economical.

Iron in its pure form is not used for building construction, but when other elements are mixed in with it, it becomes an acceptable form for building bridges and buildings.

Cast Iron

Cast iron is an alloy of pure iron, containing 2 to 4% carbon and other impurities, such as sulfur and phosphorus, but it still lacks good tension capabilities, as it maintains a brittleness; however, it does have relatively good compressive strength and hence, it was used during the 18th and 19th centuries for infrastructure.

WikipediaCommons William Williams The Iron Bridge, Coalbrookdale, Shropshire

Cast iron structures were initially found in the UK, where The Iron Bridge in Coalbrookdale, Shropshire, England was built in 1781 was the first large-scale cast-iron structure to be constructed.

Cast iron was used in the 19th and 20th-century buildings as well. In fact, there is a whole section in New York City that is called the Cast Iron District, also known as SOHO.

Wrought Iron

Wrought iron is also an iron alloy with a much lower carbon content than cast iron.  It is a tougher material than cast iron and is also malleable, ductile, and corrosion-resistant.

Wrought iron was a step above cast iron and since it was malleable, it was given the name wrought since it could be hammered into shape while it remained hot. It is a prerequisite to mild steel, also called low-carbon steel, the first of the steel alloys. 

Early on, wrought iron was refined into steel. In the 1860s, as ironclad warships and railways were built with these iron alloys, but with the advent of the Bessemer process, making steel became less costly to make, wrought iron was eventually halted to make way for the even less expensive and stronger iron alloy called steel.


Besides being an essential component for healthy blood in our bodies, iron became an essential component for weapons and later, building materials.

As such, numerous bridges and buildings have been constructed during the 18th, 19th, and 20th centuries, but as the industrial revolution advanced and the making of materials became automated, new alloys of iron were created, specifically, steel and this, along with concrete led to the construction of buildings, bridges, and skyscrapers we see today all over the world.

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