Sigur Ros also use a 'xylophone' made out of shale (i think) that was used in a performance called 'Odin's raven magic' http://www.youtube.com/watch?v=gxAAXblqtrc
this was shown in part in a documentary on icelandic music called 'screaming masterpiece
http://www.youtube.com/watch?v=gxAAXblqtrc
this was shown in part in a documentary on icelandic music called 'screaming masterpiece