It is found in the minerals gadolinite, cerite, samarskite and fergusonite, and is usually obtained from cerite.
It is usually found associated with tantalum, the chief minerals containing these two elements being tantalite, columbite, fergusonite and yttrotantalite; it is also a constituent of pyrochlor, euxenite and samarskite.
The rare earth metals are found in the minerals gadolinite, samarskite, fergusonite, euxenite and cerite.