from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A lustrous, blackish-brown rare-earth mineral consisting primarily of cerium, erbium, titanium, uranium, and yttrium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A dark brown lustrous mineral that is a mixed oxide of cerium, erbium, titanium, uranium, yttrium and other more common metals, with the chemical formula (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6.
from the GNU version of the Collaborative International Dictionary of English
- n. A brownish black mineral with a metallic luster, found in Norway. It contains niobium, titanium, yttrium, and uranium, with some other metals.
from The Century Dictionary and Cyclopedia
- n. A brownish-black mineral with a submetallic luster, found in Norway, which contains the metals yttrium, niobium (columbium), titanium, uranium, and some others.
In 1879 a Swedish chemist named Lars Fredrik Nilson was looking for rare earth elements in the minerals euxenite and gadolinite when he discovered erbium and ytterbium; scandium was later separated from the ytterbium.