Magnetite, which is nothing but Iron oxide is used as a natural magnet and is commonly called lodestone.

A natural magnet refers to a magnet that is found in nature without any human intervention or artificial manufacturing. These magnets occur in the Earth’s crust and are made of a naturally magnetized mineral known as magnetite (Fe₃O₄).

The term "lodestone" comes from the old English word "lode," meaning "course" or "way," because these stones were known to always point in the same direction when suspended in water or on a pivot, thus acting like a natural compass.

Magnetite itself is the primary mineral that naturally exhibits magnetic properties. It is often found in areas with volcanic activity and is considered the first naturally occurring magnet. The magnetic properties of lodestones were recognized by ancient civilizations and played a significant role in the early development of navigation.