Editing Scandium (section)

===Occurrence===
In [[abundance of elements in Earth's crust|Earth's crust]], scandium is not rare. Estimates vary from 18 to 25&nbsp;ppm, which is comparable to the abundance of [[cobalt]] (20–30&nbsp;ppm). Scandium is only the 50th most common element on Earth (35th most abundant element in the crust), but it is the 23rd most common element in the [[Sun]]<ref name="rubber">{{cite book|title= CRC Handbook of Chemistry and Physics|first= David R.|last= Lide|date= 2004|isbn= 978-0-8493-0485-9|pages= [https://archive.org/details/crchandbookofche81lide/page/4 4–28]|publisher= CRC Press|location= Boca Raton|url-access= registration|url= https://archive.org/details/crchandbookofche81lide/page/4}}</ref> and the 26th most abundant element in the stars.<ref>{{Cite web |title=Chemistry for Kids: Elements - Scandium |url=https://www.ducksters.com/science/chemistry/scandium.php |access-date=2024-06-12 |website=www.ducksters.com}}</ref> However, scandium is distributed sparsely and occurs in trace amounts in many [[mineral]]s.<ref>{{cite book |first= F.|last= Bernhard|chapter= Scandium mineralization associated with hydrothermal lazurite-quartz veins in the Lower Austroalpie Grobgneis complex, East Alps, Austria|title= Mineral Deposits in the Beginning of the 21st Century|date= 2001|isbn= 978-90-265-1846-1 |publisher= Balkema |location= Lisse}}</ref> Rare minerals from Scandinavia<ref name="Thort">{{cite journal|title= Scandium – Mineraler I Norge|first= Roy|last= Kristiansen|journal= Stein|date= 2003|pages= 14–23|language= no|url= http://www.nags.net/Stein/2003/Sc-mineraler.pdf}}</ref> and [[Madagascar]]<ref name="Mada">{{cite journal|journal=Geological Journal|volume= 22|page= 253|date= 1987|title= Mineralized pegmatites in Africa|first= O.|last= von Knorring|author2=Condliffe, E. |issue= S2|doi= 10.1002/gj.3350220619|bibcode= 1987GeolJ..22S.253V}}</ref> such as [[thortveitite]], [[euxenite]], and [[gadolinite]] are the only known concentrated sources of this element. Thortveitite can contain up to 45% of scandium in the form of [[scandium oxide]].<ref name="Thort" />

The stable form of scandium is created in [[supernova]]s via the [[r-process]].<ref>{{cite journal|author= Cameron, A.G.W.|title=Stellar Evolution, Nuclear Astrophysics, and Nucleogenesis |journal=CRL-41|date=June 1957|url=http://www.fas.org/sgp/eprint/CRL-41.pdf}}</ref> Also, scandium is created by [[cosmic ray spallation]] of the more abundant [[iron]] nuclei.
*<sup>28</sup>Si + 17n → <sup>45</sup>Sc (r-process)
*<sup>56</sup>Fe + p → <sup>45</sup>Sc + <sup>11</sup>C + n (cosmic ray spallation)