thanks magisy
mtmckinley, I can Ctrl-D one to you
Grev_Mivlos, I think it's to much hassle with MR, Maxwell gives better results in less human time (tweaking) but more computer-time (render)

I changed the IOR on the dice and now it looks much better and a lot more how my real dice looks. Also added some glitter to the foam, looks a little better, but not good enough.