What do you call a naturally magnetized piece of mineral?
And the answer: a lodestone.
Taken from the mineral known as magnetite, a lodestone is a naturally occurring magnet and can attract metal. Some historians believe that more than 1,000 years ago, scientists in China created the first compass by rubbing a piece of iron against magnetite, causing it to point north and south.
The powerful magnetism of the lodestone is indeed an ancient phenomena. These highly rare stones were first empirically analyzed by a 16th century scientist named William Gilbert – who was among the first to generate substantial evidence for the existence of our Earth's magnetic poles – yet knowledge of lodestones and magnetites dates back even further. According to Greek legend, naturally occurring magnetic rocks were first discovered by a shepherd whose sandals suddenly stuck to the ground. The iron nails in his sandals had become attracted to a magnetic rock, which soon earned the name "Magnetite" after Magnesia, where it was found. Also known as lodestone, the rock was highly prized for its magnetic properties.
In ancient Egypt, magnetism was used to perform tricks and visually impressive feats. With the help of a few strategically placed magnets, objects of worship were made to float in mid-air or appear suspended by an unseen force. Meanwhile, lodestones were used to help defend the emperor's palace in China. By magnetically charging the palace gates, armies clad in metal and equipped with steel-tipped arrows stood no chance – their weapons were rendered useless against magnetic forces.
Today, lodestones are still used to orient compasses and magnetize steel needles. They are also often used in classrooms for their demonstrable qualities of magnetism. Learn more about this fascinating rock here.