The triakis truncated tetrahedron is a convex space-filling polyhedron which is the shape of the Voronoi cell
of carbon atoms in diamond. It can be constructed from the truncated
tetrahedron by adding a vertex at the centroid of each of the four removed tetrahedron
and connecting it to those tetrahedra's base vertices.
A net for the solid is shown above. As can be seen, the solid's faces consist of four regular hexagons and 12 isosceles triangles.
The skeleton for the solid is illustrated above in two
embeddings.
