By Jason Thompson | Updated Mar 24, 2022
Magnets, whether crafted from rare‑earth metals or natural minerals, produce magnetic fields that interact with other magnets and certain ferromagnetic metals. Among the diverse array of magnetic materials, neodymium and hematite magnets stand out for their contrasting properties.
Neodymium magnets are renowned for their exceptional coercivity and magnetic energy density, making them indispensable in high‑performance applications such as electric motors, hard‑disk drives, and MRI scanners. Hematite magnets, on the other hand, exhibit very low magnetic strength and are typically limited to hobbyist toys and simple decorative items.
Neodymium is a true ferromagnet. Its crystal lattice aligns readily in an external field, producing a strong, stable magnetic moment. Hematite is close to antiferromagnetic; its spins largely cancel each other out, so it only displays a noticeable magnetic response when heated, and even then the induced field is weak.
Neodymium magnets are metallic and exhibit a bright silver sheen. Hematite, a mineral composed mainly of iron(III) oxide (Fe₂O₃), comes in a range of hues—from reddish‑brown to gray and black—depending on impurities and crystal structure.
Neodymium is an element produced through the natural nucleosynthesis processes that formed the periodic table, and is now mined from rare‑earth ore deposits. Hematite forms as a secondary mineral when iron‑bearing rocks weather under atmospheric conditions or in aqueous environments, leading to rust‑like deposits that can be harvested for magnet production.
