White crystal aggregates of the rare Na-Sr phosphate mineral nastrophite from the type locality in Karnasurt (Karnasurt Mountain, Lovozero Massif, Murmansk Oblast, Russian Federation). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Nastrophite
Nastrophite is an IMA-recognized mineral species in the phosphate class, with the chemical formula NaSr(PO₄)·9H₂O.
It crystallizes in the cubic crystal system (space group P2_13).
Key properties: Mohs hardness 2; specific gravity 2.05; Vitreous luster.
IMA symbol Nsp, IMA status: approved, named in 1980.
Found in pegmatitic veinlets in cancrinite and nepheline syenites.
It is found associated with Vuonnemite, steenstrupine-(Ce), ilmajokite, mountainite (Mt. Karnasurt, Kola Peninsula, Russia); K-feldspar, sodalite, analcime, natrolite, davyne.
The name refers to sodium, NAtrium, STROntium, and PHosphorus in the composition.