A lot of outstanding white single crystals and groups of the rare mineral nacaphite from the type locality in Rasvumchorr (Khibiny, Kola, Russian Federation). Associated minerals following the old label of F.Bauer are: nefedovite and apatite. — Photo: David Hospital · CC BY-SA 4.0
Nacaphite
Nacaphite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Na₂Ca(PO₄)F.
It crystallizes in the triclinic crystal system (space group R3m).
Key properties: Mohs hardness 3; specific gravity 2.85; Vitreous luster; optically biaxial.
IMA symbol Ncp, IMA status: approved, named in 1979.
A rare late-stage hydrothermal mineral in ijolite-urtite pegmatite.
It is found associated with Thermonatrite, villiaumite, aegirine, apatite, barytolamprophyllite (Khibiny massif); interstial with nepheline, potassic arfvedsonite, microcline.
The name refers to sodium, NAtrium, CAlcium, and PHosphorus in the composition.