Kamiokite
Kamiokite is an iron-molybdenum oxide mineral with the chemical formula Fe2Mo3O8. The name kamiokite is derived from the locality, the Kamioka mine in Gifu Prefecture, Japan, where this mineral was first discovered in 1975.
Kamiokite is a hexagonal system with equal axes a1, a2, a3. These three axes of the kamiokite crystal are uniformly separated by 120°. Kamiokite is an anisotropic mineral, meaning that light travels through the mineral in different directions and velocities. Kamiokite is strongly pleochroic and is also birefringent.