Details of the igneous crystalline basement rock on Orkney, found near Stromness, formed of a high proportion of coarse pink or greyish poorly foliated granite that grades locally into granite-gneiss. It lies beneath the Devonian rocks. It is often veined, and the four photographs in this post show details of different cut faces on a boulder, demonstrating different textures and colours in the same rock. The facet illustrated in the header image is further ornamented by patches of two differently-coloured lichens scattered across the surface.