This puzzle does not work!
The following article was taken from the original post on TwistyPuzzles.com in 4/2014.
This is a second version of Dave’s Diamond. It has been redesigned larger for stability. It’s much much better, so I’ve also made a video showing some of the possible moves.
For discussion of the puzzle, see the original topic here:
viewtopic.php?f=15&t=27007&hilit=dave%27s+diamond