Bizarre UFO-like Rock photographed by Mars Rover Curiosity

Sometimes Mars rocks have pretty interesting shapes like the next weird UFO-like rock photographed by Mars Rover Curiosity on September 10, 2015 (SOL 1100).

Like the floating spoon, also this rock seems to be floating above the Martian surface but that could be just a trick of the eye.


Is it possible that due to natural processes the rock has changed into a bizarre UFO-like shape or do we see here something what is artificially created by ancient races?