Apparently, as part of the Stonehenge Series, Zerberus is building a guitar body made of Granite. That strikes me as a little Bizarre/Heavy. I checked their website and didn't see any Granite guitars for sale but they did have one of these instruments displayed at Musikmesse.
Using stone as a guitar body material was new to me but apparently there are a few of these guitars around. Here's a guy on utube showing off the sustain on his stone body guitar.
Here's a link to their site if you want to see some of their more conventional guitars:
