I have worked as an independent Radio Frequency consultant in the telecommunications industry for 7 years and have over 15 years of hands on experience in Radio Frequency engineering.
A Lodestone is the strongest of only two naturally existing minerals that are permanently magnetised. It was first discovered in 500BC. Imagine the wonder of the ancients at discovering a Lodestone and its seemingly magical attraction on a piece of iron.
The static magnetic field produced by a Lodestone is a special case of the electromagnetic field. We now know that electric and magnetic fields are intimately connected hence the term electromagnetism. However, in static conditions an electric field cannot be detected around the static magnetic field (and vice versa).
The discovery of Lodestone was the beginning of the electromagnetic revolution for man. The compass was the first practical application of Lodestone and its electromagnetic field was used for navigation across the oceans.
Today, electromagnetic fields have been harnessed to power our electronic devices and send information using electromagnetic waves to our mobile phones. They are the driving force behind our economy.