The salts of praseodymium are green in colour, and give a characteristic spark spectrum.
The atomic weight of praseodymium is 140.5.
Meyer thinks that the susceptibilities of the metals praseodymium, neodymium, ytterbium, samarium, gadolinium, and erbium, when obtained in a pure form, will be found to equal or even exceed those of the well-known ferromagnetic metals.
Lanthanum has retained its elementary character, but recent attempts at separating it from didymia have led to the view that didymium is a mixture of two elements, praseodymium and neodymium (see Didymium).
The glass in these lenses contains three elements (neodymium, erbium, and praseodymium) which enhance color perception while improving both contrast and depth perception.