Great supersemicupola

The great supersemicupola is the first known example of a 7/2-7/2-3 acrohedron, i.e. a polyhedron with all regular faces that has two heptagrams and a triangle meeting at a vertex. It was discovered by Mason Green in 2005 along with the 7-7-3 small supersemicupola. Most acrons containing heptagons have no known acrohedron, so the existence of this acrohedron is rather unusual.