It is a rare mineral, it was noticed first in Norway in 1854. Its name origins from the greek astron (star) phyllon (leaf) words. Its look is often radial spiky, lamellar, sometimes has a star-like shape. Mostly can be found in volcanic rocks, often in syenite, commonly with feldspars, micas, titanite, zircon, aegirine and nepheline. Localities: Russia (Kola Peninsula), Canada (Mont-Saint-Hilaire, Québec), USA (Pikes Peak, Colorado), Norway (Brevig), Greenland etc.