von Necturus » 5. Sep 2006 17:07
freedom, its concrete that - i think - was produced under high pressure while supplying air. hence you get a "spongy" material thats extremely leightweighted, saves a lot of material and has very good isolating characteristics. I wouldnt know the english name for it though, probably the description might help you find out more ?
As Gorilla displayed, it can also be easily carved by any tool more stable then a plastic knife.
Necturus