The smallest possible number of vertices a polyhedral nonhamiltonian graph can have is 11, and there exist 74 such graphs, including the Herschel graph and the Goldner-Harary graph. The Herschel graph is the unique 11-vertex nonhamiltonian polyhedral graph having the minimum possible number of edges (18). It was used by Owens (1980) in the construction of the 76-node Owens graph, which is the smallest known polyhedral quartic nonhamiltonian graph.
The Herschel graph is implemented in the Wolfram Language as GraphData["HerschelGraph"].
It has graph spectrum
The canonical polyhedron corresponding to the Herschel graph may be termed the Herschel enneahedron.