From the Etsy store where you can purchase one:
I’ve been sucked in to playing Notch’s awesome game, Minecraft (if you have not played it, go get it now!) and wanted a little souvenir to remind me of it on my desk at work. The cube is just over 2.5″ on each side, and sealed with 6 coats of clear lacquer to help keep it durable. It isn’t intended as a toy, but I think these look really nice sitting on my desk.
I think one of these would look nice on my desk as well.