Dysprosium - 66Dy: historical information
A lttle dysprosium oxide was identified in 1886 by Paul-Emile Lecoq de Boisbaudran as an impurity in erbia (erbium oxide), but the element itself not isolated at that time. Neither the oxide nor the metal was available in relatively pure form until the 1950s following the development of ion-exchange separation and metallographic reduction techniques.