Erbium is a solid rare-earth element of the lanthenide series.
It was found by Carl Mosander in 1842. The names erbia and terbia became confused and so after 1860, Mosander's terbia was known as erbia , and after 1877, the earlier known erbia became terbia . The erbia of this period was later shown to consist of five oxides, now known as erbia, scandia, holmia, thulia, and ytterbia. Two men named Klemm and Bommer first produced reasonably pure erbium metal in 1934 by reducing the anhydrous chloride with potassium vapor. The pure metal is soft, bendable and shape able.