Ijolite

File:Ijolite (Oka Carbonatite Complex, Early Cretaceous, 124-125 Ma; Oka Niobium Mine, Quebec, Canada) (14822252052).jpg

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>Template:Cite journal</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, IijokiTemplate:, 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.Template:Sfn Ijolite was first defined and named by Finnish geologist Wilhelm Ramsay.<ref name=UppslagsverketFi>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The pyroxene is Template:Clarify span, 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.Template:Sfn

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,Template:Sfn but is now regarded as a variety of leucitite.<ref name="GuptaYagi1980">Template:Cite book</ref>

References

• {{#if: |

   |{{#ifeq: Ijolite |
                |{{#ifeq: |
                             |
                             |
                           }}
                |
               }}
  }}{{#ifeq:  |
   |{{#ifeq:  |
                                    |This article
                                    |One or more of the preceding sentences
                                   }} incorporates text from a publication now in the public domain: 
  }}{{#invoke:template wrapper|{{#if:|list|wrap}}|_template=cite EB1911
   |_exclude=footnote, inline, noicon, no-icon, noprescript, no-prescript, _debug

   | noicon=1
  }}{{#ifeq:  ||}}