Dysprosium [SEP] time of discovery
Dysprosium
Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a rare earth element with a metallic silver luster. Dysprosium is never found in nature as a free element, though it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is Dy.
Dysprosium was first identified in 1886 by Paul Émile Lecoq de Boisbaudran, but it was not isolated in pure form until the development of ion exchange techniques in the 1950s
Discovery and early history Early classification.
Before the time that ion-exchange methods and elution were available, the separation of the rare earths was primarily achieved by repeated precipitation or crystallisation. In those days, the first separation was into two main groups, the cerium earths (scandium, lanthanum, cerium, praseodymium, neodymium, and samarium) and the yttrium earths (yttrium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). Europium, gadolinium, and terbium were either considered as a separate group of