It was discovered in 1880 by the Swiss scientist Jean de Marignac. Marignac named the element for Johan Gadolin, a Finnish chemist.
Gadolinium is found with other rare earths in the mineral gadolinite.
It is sometimes used in control rods of nuclear reactors to absorb neutrons produced inside the reactor. Gadolinium's chemical symbol is Gd. The element's atomic number is 64, and its atomic weight is 157.25. It is strongly magnetic at room temperature, but loses its magnetism when heated slightly. Larry C. Thompson, Ph.D., Professor of Chemistry, Univ. of Minnesota, Duluth.