Basic Information

Name: Erbium 
Symbol: Er 
Atomic Number: 68 
Atomic Mass: 167.26 amu 
Melting Point: 1522.0 °C (1795.15 K, 2771.6 °F) 
Boiling Point: 2510.0 °C (2783.15 K, 4550.0 °F) 
Number of Protons/Electrons: 68 
Number of Neutrons: 99 
Classification: Rare Earth 
Crystal Structure: Hexagonal 
Density @ 293 K: 8.795 g/cm3 
Color: grayish
Date of Discovery: 1843 
Discoverer: Carl Mosander 
Name Origin: Ytterby (a town in Sweden) 
Uses: ceramics 
Obtained From: heavier rare earth minerals