Up for sale are 4 natural fluorite octahedron crystal. Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. Metaphysically: Fluorite is a highly protective and stabilizing stone, useful for grounding and harmonizing spiritual energy.