Natural Slate is a plate structure, the basic rock is not recrystallized, is a metamorphic rock, original rock to mud, silty or neutral tuff, management direction along the plate can peel into thin slices.The color of slate with the impurities they contain varies Slate With iron for the red or yellow ; containing carbon quality for the black or gray ; with calcium in the case of hydrochloric acid will bubble, so named for the color of its general classification, as will the green slate, black slate, calcareous slate. Slate can be used as building materials and decoration materials, in ancient times used to do in areas rich in slate tiles.Slate generally do not contain minerals .