Lanthanum

Uses

Lanthanum’s most distinctive application is in optical glass: adding lanthanum oxide raises the glass’s refractive index while limiting chromatic aberration, so it’s used in higher-quality camera lenses, telescopes, and other precision optics where sharper, more accurate images matter. Lanthanum-based alloys are also a core component of nickel-metal hydride batteries, which store and release energy through a hydrogen-absorbing electrode and became especially well known for powering early hybrid vehicles.

In the petroleum industry, lanthanum-containing catalysts play a role in fluid catalytic cracking, a process refineries use to break heavy crude oil fractions down into more valuable, lighter fuels.

History

Lanthanum was discovered in 1839 by Swedish chemist Carl Gustaf Mosander, who was investigating what other chemists believed to be pure cerium nitrate and found that it actually contained a second, previously unrecognized element mixed in. He named it lanthanum, from the Greek lanthanein, meaning “to lie hidden,” a nod to how long it had gone unnoticed within cerium samples. That discovery turned out to be the first crack in a much bigger puzzle, as Mosander and later chemists went on to find several more closely related elements hiding in the same minerals — the group that lanthanum eventually gave its name to.