Element Gadolinium, Gd, Lanthanide

Gadolinum (previously known as Victorium) is, like samarium, neither one of the most nor one of the least abundant of the rare earth elements. It forms a colourless oxide and a series of colourless salts, which exhibit no selective absorption in the visible region of the spectrum, but show an ultraviolet absorption spectrum. Gadolinia was doubtless one of the main constituents of the " terbia" obtained by the earlier workers in the field of rare earth chemistry.

Since gadolinium was discovered by Marignac and examined by Lecoq de Boisbaudran, the isolation of pure gadolinia has been studied by Bettendorf, Benedicks, Demargay, Marc, and by Urbain and Lacombe.

In 1794 Johan Gadolin the professor of chemistry at the Royal Academy of Abo, received a sample of mineral found in a quarry in the Swedish village Ytterby near Stockholm, by careful experiments, he isolated a rare earth oxide. Several years later Ekeberg found beryllium in it and called it yttria. Mosander splitting old yttria into three new earths, yttria proper, erbia, and iterbia. Mosander's erbia was confirmed by Marc Delafontaine in 1878 and renamed terbia; Delafontaine's terbia was split by Jean de Marignac in 1880 into an earth to which he gave the provisial name Yα and true terbia.

In 1879 Francois Lecoq de Boisbaudran produced a more pure form of the earth Yα. After a correspondence with Marignac Lecoq de Boisbaudran announced that Marignac had chosen to give Yα the name gadolinia (the oxide of gadolinium), after the mineral gadolinite. Gadolinite is named after Johan Gadolin. Pure gadolinium was extracted in 1896.

Lanthanide Gadolinium crustal abundance is 5.4x10^-4 mass %, in seawater 6x10^-7 mg/L. Along with other rare earth elements it is contained in monazite, bastnasite, in gadolinite, xenotime and apatites.