Make your own synthetic diamond

http://www.flickr.com/photos/jurvetson/ / CC BY 2.0

This is a cool project, but it makes really tiny diamonds (what can we really expect from home-made? Lol!). Still, it's good if you're trying to demonstrate the science involved in how a diamond is made to a kid. For me, after reading the instructions, I think it's more likely that this experiment would break my micorwave first, but hey, it worked for the dude that authored this instructable, so who knows?

http://www.instructables.com/id/SM2TX1AFSUUXNG0/