Outstanding pink with a distinct violet hue crystal aggregates of the extremely rare silicate kvanefjeldite from the type and only known locality worldwide in Greenland: Kvanefjeld, Ilímaussaq, Narsaq, Kujalleq, Greenland. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Kvanefjeldite
Kvanefjeldite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₄CaSi₆O₁₄(OH)₂.
It crystallizes in the orthorhombic crystal system (space group Pcab).
Key properties: Mohs hardness 5.5–6; specific gravity 2.55; Vitreous, pearly on {010} cleavage luster; optically biaxial.
IMA symbol Kva, IMA status: approved, named in 1982.
Occurs as patches, streaks, and veinlets cutting arfvedsonite-bearing nepheline syenite; probably of late-stage hydrothermal origin.
It is found associated with Villiaumite, analcime.
The name is taken from the type locality, which is Danish for the mountain where the angelica grows.