1. Is stable in air & doesn't oxidize as quick as other rare earth metals.
2. Erbium is malleable(Able to be hammered down).
3. can be used to add pink to cubic zirconia.
4. Not a required element for the human body, but might help with metabolism.
5. Compounds like Erbium oxide are used in safety glasses for welders and metal works.
6. Divided into the Lanthanide & Actinide series.