14 - pyritohedron previous next

But, this sort of dodecahedron is not regular, because the crystal structure of iron pyrite is cubical. When cubes do their best to act like a regular dodecahedron, it's called a pyritohedron:

This picture is from Steven Dutch's webpage on Building Isometric Crystals with Unit Cells, part of his website called Symmetry, Crystals and Polyhedra.