Slate is a metamorphic product of shale. It can be a fine-grained brittle rock which splits readily into thin smoothed-faced layers or sheets (slaty cleavage). Such cleavage is largely due to the alignment of platy minerals into parallel planes. Slates are generally dark grey, green or black in colour. Individual grains cannot be distinguished with the naked eye.
Metamorphic Aureole on Skiddaw, near Threlkald, Lake District.
Pecca Quarry, Ingleton Waterfalls Walk.