Most minerals nicknamed after a property they merely resemble don’t actually have that property. Magnetite is the exception. It’s genuinely, physically magnetic, strongly enough that a natural magnetite specimen, a lodestone, can pick up iron filings and paperclips directly, no battery or coil required.
An iron oxide with an unusual electron arrangement
Magnetite is an iron oxide, Fe3O4, containing iron in two different oxidation states within the same crystal structure, and that specific arrangement is what produces its magnetism: the unpaired electrons around those iron atoms align their magnetic fields in the same direction throughout the crystal, rather than canceling each other out the way they do in most iron-bearing minerals, including the closely related hematite. It’s a genuine physical property, not a folk association, in the same category as quartz’s real piezoelectric effect, and one of the very few minerals that will visibly deflect a compass needle held nearby.
A compass before there were compasses
Naturally magnetized magnetite, lodestone, is widely credited as the material behind the earliest magnetic compasses, used for navigation in China as early as the Han dynasty, long before anyone understood the physics of why it worked. Today magnetite remains one of the most economically important iron ores mined worldwide, and its magnetic behavior is put to more precise use in geology: because magnetite crystals lock in the direction of Earth’s magnetic field at the moment they cool, geologists read ancient rock formations for frozen magnetite orientations to reconstruct how continents have drifted and rotated over hundreds of millions of years, a record written directly into the mineral itself.
