I realise it's a crystal lattice, but the diagrams merely show the edges going on forever, how diamonds have fixed shapes, what happens at edges? Surely there aren't just carbon bonds floating around.
I did some googling and it seems that graphite transformation of diamond is far too slow to ever worry about. I had my suspicions about what was happening to the "loose" electrons as #16 described, but I don't have the education in that area to have reached a conclusion. Thanks, #16.
Recent research is showing us that the molecular world is a lot more chaotic than previously imagined (at least by laymen). Water forms many molecular structures, which makes me wonder if microwave-heated water is really different than convection-heated water, inasmuch as Human consumption is concerned.