The next member of the Ora family, moving up to dodecahedral symmetry. A mysterious piece with a large and hidden inner volume.

On Paul Nylander's marvelous math-art page, there's a similar image titled "Knotted Surface". It was done with my blessing, and there's also a beautiful movie showing how it's topologically equivalent to a face-punctured triacontahedron. Now I understand this piece much better!