Magnet
Rare earth (lanthanoid) elements have a partially occupied "f" electron shell (which can accommodate up to 14 electrons). The spin of these electrons can be aligned, resulting in very strong magnetic fields, and therefore, these elements are used in compact high-strength magnets where their higher price is not a concern. The most common types of rare-earth magnets are samarium-cobalt and neodymium-iron-boron (NIB) magnets.
Magnetic mineralogy
Extraterrestrial environments being low in oxygen, minerals tend to have very little . The primary magnetic phase on the Moon is ferrite, the body-centered cubic (bcc) phase of iron. As the proportion of iron decreases, the crystal structure changes from bcc to face centered cubic (fcc). Nickel iron mixtures tend to exsolve into a mixture of iron-rich kamacite and iron-poor taenite.