The rhombic hexecontahedron is a pretty shape; it's used as the symbol for Wolfram Alpha. It's also non-convex, so it can't be used as a die... or can it? Since it's a facetting of the regular dodecahedron, it essentially lands on five vertices which are the corners of one face of the enclosing regular dodecahedron. So with a little creative labelling, it can certainly be used as an ordinary d12.
As usual, order at your own risk until I've put up pictures of the actual print.
OK, got my print of this, and I have to say that as it stands, it's something of a failure. The points are so sharp and fine that the colors actually "bleed" across to other faces a little, here and there. And the numbers are too bold and dark and tend to look like big black blobs. Besides, the points are too pointy for using as a die. There are good uses for full-color sandstone: this isn't one of them. Maybe I can redesign.