View source for Ijolite

{{short description|Igneous rock consisting essentially of nepheline and augite}}
[[File:Ijolite (Oka Carbonatite Complex, Early Cretaceous, 124-125 Ma; Oka Niobium Mine, Quebec, Canada) (14822252052).jpg|thumb|'''Ijolite''' (Oka Carbonatite Complex, Early Cretaceous, 124-125 Ma; Oka Niobium Mine, [[Quebec]], Canada)]]
'''Ijolite''' is an [[igneous rock]] consisting essentially of [[nepheline]] and [[augite]].<ref>{{Cite journal|last1=Kresten|first1=Peter|last2=Troll|first2=Valentin R.|date=2018|title=The Alnö Carbonatite Complex, Central Sweden|url=https://link.springer.com/book/10.1007/978-3-319-90224-1|journal=GeoGuide|language=en-gb|doi=10.1007/978-3-319-90224-1|isbn=978-3-319-90223-4 |s2cid=135266142 |issn=2364-6497|url-access=subscription}}</ref> Ijolite is a rare rock type of considerable importance from a [[mineralogy|mineralogical]] and [[petrology|petrological]] standpoint. The word is derived from the first syllable of the Finnish words such as ''Iivaara'', ''[[Iijoki]]''{{,}} and ''[[Ii, Finland|Ii]]'', all geographical names in [[Finland]], and the [[Ancient Greek]] ''Xiflos'', a stone. Ijolite occurs in various parts of the [[Kainuu]] region of eastern [[Finland]] and in the [[Kola Peninsula]] of northwest [[Russia]] on the shores of the [[White Sea]].{{sfn|Chisholm|1911}} Ijolite was first defined and named by Finnish geologist [[Wilhelm Ramsay]].<ref name=UppslagsverketFi>{{cite web |url=http://uppslagsverket.fi/sv/sok/view-103684-RamsayWilhelm |title=Ramsay, Wilhelm |last=Lindberg |first=Johan  |date=January 19, 2011 |website=[[Uppslagsverket Finland]] |publisher= |access-date=November 30, 2017 |language=Swedish}}</ref> 

The [[pyroxene]] is {{clarify span|text=morphic|explain=obscure term|date=January 2017}}, yellow or green, and is surrounded by formless areas of nepheline. The accessory minerals are [[apatite]], [[cancrinite]], [[calcite]], [[titanite]] and [[schorlomite]], a dark-brown titaniferous variety of [[melanite]]-[[garnet]]. This rock is the [[plutonic]] and holo-crystalline analogue of the [[nephelinite]]s -volcanic equivalent and nepheline-dolerites; it bears the same relation to them as the [[nepheline syenite]]s have to the [[phonolite]]s.{{sfn|Chisholm|1911}}

A [[leucite]]-augite rock, resembling ijolite except in containing leucite in place of nepheline, is known to occur at [[Shonkin Creek]], near [[Fort Benton, Montana]], and was earlier called [[missourite]],{{sfn|Chisholm|1911}} but is now regarded as a variety of [[leucitite]].<ref name="GuptaYagi1980">{{cite book | title=Petrology and Genesis of Leucite-Bearing Rocks | publisher=Springer-Verlag | author=Gupta, A.K and Yagi, K. | year=1980 | location=Berlin | isbn=978-3-642-67552-2}}</ref>

==References==
{{Reflist}}
*{{EB1911|wstitle=Ijolite|volume=14|page=298}}
{{Rock type}}
[[Category:Plutonic rocks]]