You can turn into any stone in existence, relatively easily. Your body assumed the traits and features of whatever rock you choose. If a body part gets broken off, it won't reform, but when you transform back into a human, it will regrow. In order to turn into a rock, however, you must be holding the type of rock that you so desire. You die if your head shatters to the size of a piece that is smaller than the seed rock. For example, if you pick up a pebble, your body turns into the mineral that the pebble is composed of. However, if every piece of your head is reduced to a size smaller than the original pebble, then you die for good. Disclaimer: you can only transform once every 24 hours. Just like the chameleon skill. Except once you're a rock, you have to wait 24 hours to transform back into a human. And your head pieces can't move around without help. So if your head breaks, your pieces can't move until you turn back into the human form 24 hours after you transformed into the rock. And no, you don't feel pain while in rock form. You actually don't feel anything. Or breathe, or eat, while in rock form, you're essentially just a rock man. No need for sustenance.

Ben 10 much