From two of these substances, he discovered erbium and terbium ... of 2,352 F (1,289 C), are known. The oxide is a dark maroon or chocolate color, and 21 isotopes with atomic masses ranging ...

In one final twist, however, the spectroscopist Delafontaine, in confirming their existence, erroneously switched Mosander's original names and called the amethyst-coloured compound erbium oxide ...

Now, Zuimin Jiang at the Fudan University in Shanghai, China and co-workers 1 have shown that amorphous (non-crystalline) erbium oxide films are promising candidates as high-k dielectrics.