You need to start by boolean differencing the cube and tetrahedron out of the dodecahedron (with the delete=no option), the the tetrahedron from the cube (delete=no again) so that the objects are not occupying the same space.
Then create a dark background for your render and place a light panel to each side of the objects to provide some illumination on them. Where you have changed the IOR settings, go back to the glass norm of 1.52 or thereabouts - 12 is outside the range of natural materials. If you want an accurate IOR then you’ll find tables of values on the web.
But just a word of warning. In Rhino 6 the stock Render tool is not going to give great results. Raytraced didn’t work for me on your objects, but I’m sitting at an aging laptop which I wouldn’t normally render on, so it might work for you. Rhino 7 is much better for this. See, for example, POLL - Which image do you prefer?