Europium (Eu) is contained in the following rare earth mineral:
Bastnaesite
Monazite
Xenotime
Loparite
Euxenite
Aeschynite
Samarskite
Eudialyte
Fergusonite
Rhabdophane
Churchite
References
https://en.wikipedia.org
http://what-is-nanotechnology.com/8europium-oxide-Eu2O3-target.htm