Samarium [SEP] time of discovery
Samarium was discovered in 1879 by the French chemist Paul-Émile Lecoq de Boisbaudran and named after the mineral samarskite from which it was isolated. The mineral itself was earlier named after a Russian mine official, Colonel Vassili Samarsky-Bykhovets, who thereby became the first person to have a chemical element named after him, albeit indirectly. Although classified as a rare-earth element, samarium is the 40th most abundant element in the Earth's crust and is more common than metals such as tin. Samarium occurs with concentration up
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