{{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 mineralogical and petrological standpoint. The word is derived from the first syllable of the Finnish words such as ''Iivaara'', ''Iijoki''{{,}} and ''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 nephelinites -volcanic equivalent and nepheline-dolerites; it bears the same relation to them as the nepheline syenites have to the phonolites.{{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