Arctite (Na2Ca4(PO4)3F) is a colourless mineral found in the Kola Peninsula northern Russia. It's Mohs hardness is 5 and has a density of 3.11-3.13. Arctite is transparent with a vitreous lustre. Arctite has a perfect cleavage and a trigonal crystal system.
Common associates of arctite include aegirine, natisite, lomonosovite, umbite and thenardite.
References
Arctite Wikipedia(Text) CC BY-SA