Gadolinium /(?)/

Gad·o·lin·i·um

Gadolinium

n.
  1. A rare earth metallic element of the Lanthanide series, with a characteristic spectrum, found associated with yttrium and other rare earth elements. Symbol, Gd; it has an atomic number of 64, an atomic weight of 157.25 (C=12.011), and a valence of +3. (Chem.)