- a rare metallic element found in gadolinite and forming compounds resembling those of yttrium. Symbol: Yb; atomic weight: 173.04; atomic number: 70; specific gravity: 6.96.
- a soft malleable silvery element of the lanthanide series of metals that occurs in monazite and is used to improve the mechanical properties of steel. Symbol: Yb; atomic no: 70; atomic wt: 173.04; valency: 2 or 3; relative density: 6.903 (alpha), 6.966 (beta); melting pt: 819°C; boiling pt: 1196°C
