Editing Ytterby (section)

== Mine==
[[Quartz]] was mined in the area beginning in the 1600s for the ironworks in [[Uppland]].<ref>{{cite web |title=The Ytterby Mine / History|url=http://ytterby.org/our%20vision/history.html |website=Ytterby.org}}</ref> [[Feldspar]] was mined for local porcelain manufacture, such as [[Gustavsberg porcelain|Gustavsberg]], and the porcelain trade with [[United Kingdom|Britain]] and [[Poland]].<ref name="Voncken">{{cite book |last1=Voncken |first1=J.H.L |title=The Rare Earth Elements: An Introduction |date=2015 |publisher=Springer |isbn=978-3-319-26809-5 |pages=6, 127}}</ref> The mine is likely the first feldspar mine in Sweden, starting in 1790. Feldspar mining was likely sporadic and based on manufacture demand. This demand increased in the 1860s, leading to deeper mining efforts at Ytterby. The mine became one of the most productive quartz and feldspar mines in the country.<ref name="fort">{{cite web |author1=Knutson Udd, Lena |author2=Leek, Tommy |title=Ytterby gruva |url=http://fortv.se/Documents/Ytterby%20gruva%20dokumentation%202012%20exkl%20bilaga%20webbversion.pdf |publisher=Fortifikationsverket |access-date=6 January 2018 |language=sv |date=2012 |archive-date=7 January 2018 |archive-url=https://web.archive.org/web/20180107061900/http://fortv.se/Documents/Ytterby%20gruva%20dokumentation%202012%20exkl%20bilaga%20webbversion.pdf |url-status=dead }}</ref> Feldspar and quartz mining continued until 1933, when the mine was shut down. With 177 years of feldspar mining, it was the longest-mined feldspar mine in [[Sweden]].

Towards the end of the 1940s, the Swedish state, through the REF (''Riksnämnden för ekonomisk försvarsberedskap'') became interested in the possible usage of the mine. In 1953, the mine was renovated and used for the storage of jet fuel, [[MC 77]]. The storage method led to contamination of the jet fuel, leading to problems in jet engines that used the fuel. The storage of jet fuel ended in 1978. It was subsequently used to store diesel. In 1995, the mine was emptied, and in the following years the area was rehabilitated.<ref name="fort" />

The mined quartz and feldspar are part of a pegmatite [[dyke (geology)|dyke]] that has a NNE-SSW orientation and a dip of 60° to the west.<ref name=Almq>{{Cite book|title=Nyttosten i Sverige|last1=Lundegårdh|first1=Per H.|publisher=[[Almqvist & Wiksell]]|year=1971|isbn=|location=Stockholm|language=Swedish|pages=19−20}}</ref> The [[pegmatite]] dyke include sections of [[aplite]] and [[graphic granite]].<ref name=Almq/> The surrounding host rock is "gabbro-like [[Greensand (geology)|greenstone]]".<ref name=Almq/>