I've seen several images like this so this is by no means unique.
Again evidence of some exotic technology at play. Remember that Hutchinson reported intense heating of his melted iron block yet the power levels were very low (less than 100W).
This is an interesting feature and needs a lot of consideration in my opinion. Someone overcooked the stone!
Edited by zoser, 25 March 2013 - 07:08 PM.