It is a rare mineral as it is known from only a few localities and then not in large amounts. Luster is greasy to adamantine. Crystals are translucent to transparent, some specimens approach opaqueness. Crystal System is hexagonal. Crystal Habits include small prismatic or platy crystals, some demonstrating a hemimorphic character.
Fracture is conchoidal.
Streak is white. Notable Occurrences include the type locality of Narsarsuk , Greenland. Other localities include the mines of Mont Saint-Hilaire , Quebec and Kibina, Kola Peninsula , Russia.