Iron is the most useful of all metals, and of all metals it is the most widely distributed in nature. It forms a twentieth part of the world's crust. It is essential to life of all sorts. It is found in the green chlorophyll of plants and in the blood of animals. It occurs in meteorites. The color spectrum shows that iron is present in the Sun. There is an iron mountain near Durango, Mexico. It is a projecting back-bone or dike of solid iron ore,—a huge mass one mile long, a third of a mile wide, and 450 to 650 feet high. Similar hills in Missouri are known as Iron Mountain and Pilot Knob.
Iron meteorite