Dodecahedrons of pyrite, also known as pyritohedrons, are not regular dodecahedrons. The regular dodecahedron, formed by twelve identical flat faces, one of the five regular Platonic solids of ancient times, does not exist in inorganic crystals. The pyritohedrons as here displayed are "false" dodecahedrons, with non-identical faces adjusting themselves to each other at different angles, which alternate with varying numbers of small faces in between