Editing Ytterbium (section)

==Occurrence==
[[File:Euxenite - Vegusdal, Norvegia 01.jpg|thumb|[[Euxenite]] ]]
Ytterbium is found with other [[rare-earth element]]s in several rare [[mineral]]s. 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. Reserves of ytterbium are estimated as one million [[tonne]]s. 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. [[chemical compound|Compounds]] of ytterbium are rare and have not yet been well characterized. The abundance of ytterbium in the Earth's crust is about 3&nbsp;mg/kg.<ref name="history">{{cite book|url=https://archive.org/details/naturesbuildingb0000emsl|url-access=registration| pages= [https://archive.org/details/naturesbuildingb0000emsl/page/492 492]–494|title = Nature's building blocks: an A-Z guide to the elements| author =Emsley, John | publisher= Oxford University Press| date = 2003| isbn = 978-0-19-850340-8}}</ref> 

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 that it has few commercial applications.<ref name="history" /> Microscopic traces of ytterbium are used as a [[dopant]] in the [[Yttrium aluminium garnet|Yb:YAG laser]], a [[solid-state laser]] in which ytterbium is the element that undergoes [[stimulated emission]] of [[electromagnetic radiation]].<ref>{{Cite journal | last1 = Lacovara | first1 = P. | last2 = Choi | first2 = H. K. | last3 = Wang | first3 = C. A. | last4 = Aggarwal | first4 = R. L. | last5 = Fan | first5 = T. Y. | title = Room-Temperature Diode-Pumped Yb:YAG laser | doi = 10.1364/OL.16.001089 | journal = Optics Letters | volume = 16 | issue = 14 | pages = 1089–1091 | year = 1991 | pmid = 19776885| bibcode = 1991OptL...16.1089L }}</ref>

Ytterbium is often the most common substitute in [[yttrium]] minerals. In very few known cases/occurrences ytterbium prevails over yttrium, as, e.g., in [[xenotime]]-(Yb). A report of native ytterbium from the Moon's [[regolith]] is known.<ref>{{cite web |url=https://www.mindat.org/min-41858.html |title=Mindat.org |author=Hudson Institute of Mineralogy |date=1993–2018 |website=www.mindat.org |access-date=7 April 2018}}</ref>