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.
I got my print of this, and I think my expectations were a little too high for sandstone printing. The points are so sharp and fine that the colors actually "bleed" across to other faces a little, here and there. The numbers are a little too bold and dark. The points are too pointy for using as a die, but that's really my fault. It might be a little fragile for making out of full-color sandstone, as dice need to be pretty rugged if they're being used.
Note that this print is from a long time ago, and Shapeways has improved their full-color printing once or twice since then, so later prints might turn out better.