Fluorite Pyramids 25-30 mm
fluorite-octahedron cleavage Fluorite is one of the few minerals that have four directions of cleavage. If a crystal of fluorite is carefully cleaved so that the resulting form has faces of equal size and shape, an octahedron with 8 faces is formed. Miners who worked in the Cave-in-Rock fluorite district of southern Illinois used to spend their free time during lunch hours cleaving fluorite into collectible octahedrons.. It is easy to see why fluorite earns the reputation as "The Most Colorful Mineral in the World"