Magnetiitin

Magnetiitin is the Finnish name for magnetite, a naturally occurring iron oxide mineral with the chemical formula Fe3O4. It is one of the most magnetic minerals found in nature and is a common component of many igneous, metamorphic, and sedimentary rocks.

The mineral crystallizes in the inverse spinel structure and exhibits ferrimagnetism at room temperature. Its magnetic properties arise from the arrangement of iron ions in different lattice sites, giving magnetite a high saturation magnetization and a high Curie temperature of about 858 kelvin. These properties make magnetite the strongest natural magnet among widely occurring minerals and a key material in studies of Earth's past magnetic field.

Magnetite occurs broadly: in igneous rocks as primary magnetite grains, in metamorphic rocks, and in banded iron formations and placer deposits. It can form through magmatic crystallization, through hydrothermal processes, or by weathering and alteration of iron-bearing minerals. It is also present in soils and lunar and meteorite samples, reflecting its robust magnetic and chemical stability.

Economically and scientifically, magnetite serves several roles. It is mined as an iron ore in some deposits and is used as a pigment and a catalyst in chemical processes. In geology and paleomagnetism, magnetite-bearing rocks are studied to reconstruct the history of Earth's magnetic field, including plate movements and reversals. Magnetite nanoparticles find applications in medicine and environmental remediation, where their magnetic properties enable targeted delivery and separation techniques.

Health and environmental considerations are generally related to fine particulate matter; handling large, coarse crystals poses minimal risk beyond typical mineral handling, while inhalation of very fine particles should be avoided.