Quick Facts
Formation & Origin
Magnetite is an iron oxide that holds a unique place in human history - it's the most magnetic naturally occurring mineral on Earth. Certain specimens, called lodestones, are permanently magnetized and will attract iron filings and deflect compass needles. The discovery of lodestone's magnetic properties led directly to the invention of the magnetic compass, which enabled the Age of Exploration.
Magnetite forms in igneous, metamorphic, and sedimentary environments. In igneous rocks, it crystallizes directly from magma as an accessory mineral. In banded iron formations (2-3 billion years old), it's a major component alongside hematite, recording the oxygenation of Earth's atmosphere. Magnetite also forms through biological processes - magnetotactic bacteria synthesize microscopic magnetite crystals that function as biological compasses.
Not all magnetite is magnetic enough to be called lodestone. Lodestone's permanent magnetism is thought to come from lightning strikes that magnetize surface-exposed magnetite, aligning the magnetic domains permanently. This means lodestones are literally created by lightning.
Identification Guide
Magnetite is identified by its black color, metallic luster, black streak (distinguishing it from hematite's red-brown streak), hardness of 5.5-6, and magnetic properties. A simple magnet test is diagnostic - magnetite is attracted to magnets, and lodestone specimens attract iron.
Distinguish from hematite (red-brown streak vs black), ilmenite (non-magnetic, different crystal form), and chromite (slightly different streak). The magnetic test is the fastest and most reliable identification method.
Spotting Fakes
Natural magnetite is abundant and inexpensive, so faking is unnecessary. However, 'magnetic hematite' beads (which are actually synthetic barium-strontium ferrite ceramic, not hematite or magnetite) are ubiquitous in the crystal market. These manufactured beads are very strongly magnetic - much more so than natural magnetite - and have no geological origin. Real magnetite specimens have natural crystal faces or rough surfaces, not the perfect polished spheres of synthetic material.
Cultural & Metaphysical Traditions
Presented as cultural traditions, not scientific evidence
Lodestone has been used in folk magic and spiritual practice for millennia. In Hoodoo/Rootwork tradition (African American folk magic), lodestones are 'fed' with iron filings and used to attract luck, money, and love - one of the most important and continuously practiced uses of minerals in any magical tradition. Ancient Greeks called magnetite 'the bone of Horus' and attributed it to the gods. Chinese geomancers used lodestone compasses for feng shui centuries before Western navigation adopted the compass.
Where It's Found
Massive iron ore deposits, world-class
Major deposits associated with platinum mining
Historic mining, good crystal specimens
Naturally magnetic lodestone specimens
Price Guide
Good to Know
Scratch test: At hardness 5.5, Magnetite resists scratching from a knife but can be scratched by quartz. Best for pendants and earrings rather than rings.
Sources: Found in 4 notable locations worldwide, from Sweden to Bolivia.
Heft test: With a specific gravity of 5.18, Magnetite feels surprisingly heavy for its size. This weight is actually a useful identification tool.
Related Minerals
Iron oxide with red streak, not magnetic
Iron sulfide, metallic but not magnetic
Iron titanium oxide, weakly magnetic
Naturally permanently magnetized magnetite