... is a fine grained metamorphic rock formed from clay, sedimentary rock shale, and sometimes quartz. Slate ... black, brown, green, red, or purple.black roofing slate stoneClassificationSlateItem NoSS-S-001FinishedHonedColorsBlackDelivery TimeTo the contractShapeFish sacleFinished: ... for commercial use such as blackboards, flagstone, and roofing tiles. Generally, tabletops. mosaic.Color:Brown,yellow,green ...