Slate stones have various levels of porosity, hardness and compressive strength. They are best suited for exterior and interior applications. Slate renders a graceful, natural finish to any building and is more cost effective than other wall and floor coverings. All natural slate stones are fireproof and non-slippery. Slate slabs are used in architecture, flooring, wall cladding and roofing etc. The usual colors of slate are black, dark grey, greenish grey, copper and purplish grey.