Gadolinium - 64Gd: historical information
Spectroscopic lines due to gadolinium were observed by Jean Charles Galissard de Marignac in 1880 in samples of didymia and gadolinite. Gadolinia, the oxide of gadolinium, was separated by Paul-Emile Loq de Biosbaudran in 1886. The element was named for the mineral gadolinite from which this rare earth was originally obtained. The element itself was isolated only recently.