Asteroid textures

I found this great asteroid texture online http://www.filterforge.com/filters/3215.html.
Now Im only changing the colour of this texture and not UV mapping them as they are only in the scene for a few seconds, but also rock formations are jagged and un-even which this texture stretch exentuates.
I wanted to mix up the asteroid feild a bit and show an understanding of different layered materials so I added a rare rock. I was basing it on a chunk of the mineral Blue John which is a precious stone that has blue veins running through it.

This was achieved with the metal shading parameter, adding perlin marble to the diffuse colour. In the perlin marble window I tweaked the two colour parameters and then added a dent map to the first colour. It was in the dent map I added the rich dark blue of the veins. Obviously this could all be done with UVW unwrapping, but this method is faster and more random/natural looking.