pyritohedron
noun
py·ri·to·he·dron
-drən sometimes -ˌdrän
plural pyritohedrons or pyritohedra
: a pentagonal dodecahedron that is a hemihedral form of the isometric system of crystalline symmetry common to pyrite
Word History
Etymology
New Latin, from pyrito- (from International Scientific Vocabulary pyrite) + -hedron