Category Silicate mineral Crystal system Tetragonal | Strunz classification 9.DJ.05 Space group I4/m | |
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Formula
(repeating unit) Na4(Ti,Fe)4[Si8O20](O,OH,F)4. Crystal class Dipyramidal (4/m)
H-M symbol: (4/m) | ||
Narsarsukite is a rare silicate mineral with chemical formula Na2(Ti,Fe3+)Si4(O,F)11 or Na4(Ti,Fe)4[Si8O20](O,OH,F)4.
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.
References
Narsarsukite Wikipedia(Text) CC BY-SA