Ok.. So I have been tired so I didn't noticed that it has wrong scale in thickness - fixed.
Also new scene builded with new xpresso trigger for turning dynamics and visibility.
EDIT:
New file: "COIN-break_fixed" includes new polygon selections for materials, this time the materials
go direct line in the edges of the coin pieces. Also some improvements for collision (pieces do not go through
anymore)
EDIT: New "new_fix_coin_break", second try to make pieces stay on floor (pieces do not go through).
here is demo video from new scene... Just waiting Corona bug fixes so I can render this scene.
EDIT: New xpresso breaking file, better way to break objects.