Slate

Slate is a fine-grained, metamorphic stone derived from sedimentary rock shale. Slate is uniform in color, available in shades such as dark to light green, mottled purple, black, gray or dark red. Veined patterns from overseas have also recently been introduced. Unless its surface has been honed smooth, slate can be recognized by its distinct cleft pattern.

Most common uses for Slate
Residential and commercial counter tops, fireplace facing, roofing, interior & exterior (American only) wall cladding, interior & exterior (American only) paving, table tops, limited use for kitchen and bathroom counter tops, flooring, and many non-architectural uses.