Erbium (Er) is a silvery, metallic element of the lanthanide series, discovered by C. G. Mosander in Stockholm in 1843; it is named after
the Swedish town of Ytterby, where the mineral from which it was first isolated
was found. There are six naturally occurring isotopes,
and the chief ores are monazite and bastnaesite.
Twelve radioactive isotopes have been identified. Soft and malleable, erbium
is used in specialized alloys, and erbium
oxide is used as a pink colorant for glass.
Its most common isotope is 166Er
|relative atomic mass