Osumilites from Sakkabira, Japan, Obsidian Cliffs, Oregon, and Nain, Labrador have been studied by optical, infrared, and Mossbauer spectroscopy. Osumilite is an anhydrous mineral. A major proportion of the Fe2+ occurs in the channel-like cavities. Biaxial Nain osumilite is X-ray hexagonal, and does not show infrared spectroscopic evidence for Al/Si ordering. The biaxiality arises from the channel contents.