Iron is the one of the most commonly used metals on Earth. It is found everywhere on Earth. It is not only present in the minerals but also in animals and plants. It is found even in the human body. Man first began to use iron about 1200 B.C. after the Bronze Age. 5% of the Earth’s crust is iron. It is estimated that the Earth’s core contains huge quantities of iron and nickel. It is not found in a free state but occurs in a combined state with other elements. Its chief ores are — magnetite, haematite, limonite, siderite and iron pyrites. In India, these ores are mainly found in Bihar, Chhatisgarh and Orissa. To obtain the iron from these ores, they are first finely ground with coal and limestone and then heated to a high temperature in a blast furnace. The melted iron comes out from the bottom of the furnace, which, on cooling, becomes solid. The iron so obtained is called ‘pig iron’ and ‘cast iron’. It contains 5% of carbon. The iron thus produced is very brittle. After reducing the percentage of carbon from 2 to 0.2% it is converted into steel. The process of the manufacture of steel from cast or pig iron is called ‘Bessemer Process’, named after Sir Henry Bessemer, who invented it in 1850. Iron and steel are very useful for us. They are used in all the industries in some form or the other. Appliances of our daily use such as knives, scissors, blades, locks, buckets, utensils are all made from iron. Ships, planes, trains, buses, cars, scooters, etc. are also made from this useful metal. It is also used in the construction of bridges and buildings. Various kinds of nuts, bolts, pipes, etc. are also made from iron. Stainless steel, which is a very useful alloy of iron, contains 18% chromium, 8% nickel apart from steel. In India, for making stainless steels, manganese is used instead of nickel because nickel is rare in our country. Stainless steel has some special characteristics — chromium stops it from rusting and acids and alkalis also do not affect it. Other steels are made with manganese, nickel and tungsten. Iron compounds are used to make pigments, inks and films for cameras. Iron oxide is also used to make the tapes for tape recorders.