slate

A dense, fine-grained metamorphic rock formed by the compression of various sediments, as clay or shale, having good cleavage along parallel lines. Photo from Quincy, Massachusetts, 2019. (Ching, 1995)

A dense, fine-grained metamorphic rock formed by the compression of various sediments, as clay or shale, having good cleavage along parallel lines. Photo from Quincy, Massachusetts, 2019. (Ching, 1995)