It is the severed head of an alien cadaver. The dark coloured portion of the cranium is the jaw with a protective armor plate around it. To the right of the jaw is an eye. Look reall hard at it. Its lieing on the back of the head, looking upwards. Sexy, isnt it?
I really really hope you're joking
It's a cool rock, but nothing that uncommon. Here's an Earthly 2 tone rock...