Slate is a metamorphic rock formed from clay and shale. Easily split into thin sheets, slate may vary in color, occurring in browns, black and deep grays, as well as green, violet, and other variations depending on its formation. Colors in slate can often change or fade over time. Fine-grained, slate can have ribbons, some thin, others several inches wide.
The ideal roofing tile, slate can endure freezing and other temperature extremes with only a little weathering and change of color for at least 75 years, often many more. Slate can also be used for flooring and other high traffic areas that would usually show scuffing.