This material is extrapolated from a small part of a 3D scanned rock, with seam removal and mutation in Artomatix. The goal here was to extract usable tiling textures from a sample that was originally unwrapped to the specific UV layout of the source geometry, so that they could be applied to arbitrary modular 3d models. I talked about this recently with 80 Level:
https://80.lv/articles/new-era-of-3d-production-with-artomatix/