Formula: Na2(Ti,Fe3+)Si4(O,F)11
Inosilicate (chain silicate)
Crystal System: Tetragonal
Specific gravity: 2.64 to 2.83 measured, 2.81 calculated
Hardness: 7
Streak: White
Colour: Yellow, yellowish-white, greyish-white, honey-yellow, tan, greenish-yellow

Plutonic igneous environments
Metamorphic environments


At the Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Quebec, Canada, narsarsukite occurs in hornfels, igneous breccia and marble xenoliths in an intrusive alkaline gabbro-syenite complex (HOM).

At the type locality, the Narssârssuk pegmatite, Narsaarsuk Plateau, Igaliku, Kujalleq, Greenland, narsarsukite occurs in pegmatite associated with aegirine, microcline, albite, elpidite, epididymite, tainiolite and quartz (HOM).

At Sage Creek, Sweet Grass Hills, Liberty county, Montana, USA, narsarsukite occurs in quartz veins cutting an orthoclase - albite - aegirine - quartz hybrid rock in a zone adjacent to a syenite stock intruding limestone. Pectolite is the dominant vein mineral, and quartz and narsarsukite are also abundant; calcite and galena are the remaining primary minerals in the veins. The paragenetic sequence appears to be pectolite and narsarsukite oldest, followed by galena and calcite, with quartz youngest of all. Minerals associated with narsarsukite include aegirine, pectolite, calcite, feldspar, galena, manganese-bearing pectolite and quartz (AM 44.265-273, HOM). Fresh material was found at the old prospect pit on one of the veins, associated with galena, alunite, epidote, clinozoisite, apatite and feldspar (AM 20.598-601)

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