... 11,11-13MM Nature Stone Roofing Slate of Black Sheets 1.Natural finish.a little bit rough surfacenice colornon-fadingdurable2. ... black, yellow quartzite P014, rusty S1120, green, greysurface finish: natural, honed, brushed3. Step/Stairs:thickness—20-30mm / size—350* ... black, yellow quartzite P014, rusty S1120, green, greysurface finish: natural, honed, brushed, edge machine cut or bull nose4. Slate ...