Wiktionary
narsarsukite
n. (context mineralogy English) A tetragonal-dipyramidal mineral containing fluorine, iron, oxygen, silicon, sodium, and titanium.
Wikipedia
Narsarsukite
Narsarsukite is a rare silicate mineral with chemical formula Na(Ti,Fe)Si(O,F) or Na(Ti,Fe)[SiO](O,OH,F).
It was first described in 1900 for an occurrence in the Narsarsuk pegmatite in the Ilimaussaq intrusive complex of West Greenland. 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. It occurs associated with aegirine, microcline, albite, elpidite, epididymite, taeniolite, pectolite, calcite, galena and quartz.