Rocks are still one of the most fun things to do with TG.
On the bottom left you can see how the displacement function looks on a flat surface (without displacement it's very flat).
I then just added a default strata shader and my default granite shader.
All in all a relatively easy setup.
Terrain -> compute -> displace -> compute -> shade/texture -> plane/planet
I overdid GISD a bit. Strength = 1/5/96.
Since it was rendered it at 2048x2560 you also need a high radius to get similar effects to lower resolution renders.
It's not entirely realistic, but hey, let me try to wet my artistic feet

Cheers,
Martin