08/17/2026
ROCK OF THE WEEK: MAGNETITE
Some rocks can attract a magnet, and some can actually behave like magnets themselves!
Magnetite is a naturally magnetic iron-oxide mineral. It contains both iron and oxygen, and it is one of the world’s most important sources of iron.
Naturally magnetized pieces of magnetite are called lodestones. Long before modern compasses existed, people discovered that a freely moving lodestone would point roughly north and south. That discovery helped lead to the development of the magnetic compass.
Magnetite is usually black or very dark gray, feels surprisingly heavy for its size and leaves a black streak when rubbed across an unglazed ceramic surface.
A simple dark stone that helped people find their way around the world. That’s pretty impressive.
Have you ever tested a rock to see whether it was magnetic?
