{{infobox mineral | name = Narsarsukite | category = Silicate mineral | image = Narsarsukite-20220.jpg | imagesize = | alt = | caption = 1.3 cm crystal of narsarsukite from Mont Saint-Hilaire | formula = {{chem2|Na4(Ti,Fe)4[Si8O20](O,OH,F)4}}<ref name=Mindat/> | IMAsymbol = Nar<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3 |pages=291–320|doi=10.1180/mgm.2021.43 |bibcode=2021MinM...85..291W |s2cid=235729616 |doi-access=free}}</ref> | molweight = | strunz = 9.DJ.05 | dana = | system = Tetragonal | class = Dipyramidal (4/m) <br/>H-M symbol: (4/m) | symmetry = ''I''4/m | unit cell = a = 10.72, c = 7.95&nbsp;[Å]; Z&nbsp;=&nbsp;4 | color = Honey to lemon-yellow, reddish brown, brownish gray, tan, pink; may be green from inclusions; may show color zoning | colour = | habit = Occurs as flat tabular to equant, striated crystals In divergent, radiating groups; massive | twinning = | cleavage = Good on {100} and {110} | fracture = Uneven to subconchoidal | tenacity = Brittle | mohs = 5.5 - 7 | luster = Vitreous, pearly on {110} | streak = White | diaphaneity = Transparent to translucent | gravity = 2.64-2.83 | density = | polish = | opticalprop = Uniaxial (+) | refractive = n<sub>ω</sub> = 1.609 n<sub>ε</sub> = 1.630 | birefringence = δ = 0.021 | pleochroism = Weak; O = colorless to yellow; E = colorless to honey-yellow | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = <ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/narsarsukite.pdf Handbook of Mineralogy]</ref><ref name=Mindat>[http://www.mindat.org/min-2841.html Narsarsukite on Mindat.org]</ref><ref name=Webmin>[http://www.webmineral.com/data/Narsarsukite.shtml Narsarsukite data on Webmineral]</ref> }} '''Narsarsukite''' is a rare silicate mineral with either the chemical formula {{chem2|Na2(Ti,Fe(3+))Si4(O,F)11}}<ref name=HBM/> or {{chem2|Na4(Ti,Fe)4[Si8O20](O,OH,F)4}}.<ref name=Mindat/>

It was first described in 1900 for an occurrence in the Narsarsuk pegmatite in the Ilimaussaq intrusive complex of West Greenland.<ref name=Mindat/> It has also been reported from a syenite which intruded limestone in the Sweetgrass Hills, Montana, and within hornfels and marble xenoliths in the alkalic intrusive of Mont Saint-Hilaire, Quebec.<ref name=HBM/> It occurs associated with aegirine, microcline, albite, elpidite, epididymite, taeniolite, pectolite, calcite, galena and quartz.<ref name=HBM/> [[File:Narsarsukite-202076.jpg|thumb|left| Narsarsukite from Whitlash, Liberty County, Montana {size: 5.6 x 5.4 x 5.1 cm)]] {{clear left}}

==References== {{Reflist}}

Category:Inosilicates Category:Tetragonal minerals Category:Minerals in space group 87

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