Ytterbium - Occurrence

Occurrence

Ytterbium is found with other rare earth elements in several rare minerals. It is most often recovered commercially from monazite sand (0.03% ytterbium). The element is also found in euxenite and xenotime. The main mining areas are China, the United States, Brazil, India, Sri Lanka, and Australia; and reserves of ytterbium are estimated as one million tonnes. Ytterbium is normally difficult to separate from other rare earths, but ion-exchange and solvent extraction techniques developed in the mid- to late 20th century have simplified separation. Known compounds of ytterbium are rare and have not yet been well characterized. The abundance of ytterbium in the Earth's crust is about 3 mg/kg.

The most important current (2008) sources of ytterbium are the ionic adsorption clays of southern China. The "High Yttrium" concentrate derived from some versions of these comprise about two thirds yttria by weight, and 3–4% ytterbia. As an even-numbered lanthanide, in accordance with the Oddo-Harkins rule, ytterbium is significantly more abundant than its immediate neighbors, thulium and lutetium, which occur in the same concentrate at levels of about 0.5% each. The world production of ytterbium is only about 50 tonnes per year, reflecting the fact that ytterbium has few commercial applications. Microscopic traces of ytterbium are used as a dopant in the ytterbium YAG laser, or Yb:YAG laser, a solid-state laser in which ytterbium is the element that undergoes stimulated emission of electromagnetic radiation.