Fluorite combination with pyrite 118.3, Peru

Fluorite, feldspar in Czech, is a cubic mineral consisting of calcium fluoride, CaF2. It most often forms crystals in the shape of a cube, less often octahedra, sometimes rhombic dodecahedron surfaces are quite often developed. Combinations of these shapes are very common. Skeletal crystals of an octahedral habit are known, the surfaces of which are covered with oriented growths of small fluorite crystals with surfaces, conglomerations of small cubic crystals arranged into one large octahedron with stepped surfaces formed by these fused cubes are common.