Ytterbium (Yb)
Ytterbium (Yb) is contained in the following rare earth mineral:Xenotime
Fergusonite
Area of application: This element has several important uses in health care, including in certain cancer treatments. Ytterbium can also enhance stainless steel and be used to monitor the effects of earthquakes and explosions on the ground.
References
https://en.wikipedia.org
http://www.snipview.com/q/Ytterbium
https://en.wikipedia.org/wiki/Ytterbium