Here i publish a simple but nice looking Asteroid Material which i use for one of my animations.
I Highly recommended to use the experimental features of Blender to unlock the Displacement Options and set the Method to "Both", this gives a little bit more details in Geometry.
Feel free to use it for whatever you want, but i would like to know about projects with this material. :)

HDRi Image is from: http://adaptivesamples.com/2014/05/18/pano-st-lucia-interior/