Slate is quarried stone used for fireplaces, hearths, and floors in the home. Slate needs some care taken to ensure that it lasts a long time and looks its best.
Since slate is a porous stone material, it should be sealed. Get a special slate floor sealer from a company that sells flooring or a home center. The sealer penetrates the upper surface of the slate and protects it from soil and scratches, and from grease.
To clean state, brush wall surfaces occasionally to remove dust and "freshen" or dust with dusting attachment of vacuum cleaner.
Wash slate floors with detergent and water. Slate is not damaged by alkali cleaners, but strong solutions are not needed for cleaning. Rinse well and wipe the slate dry.
A water-based, self-polishing wax can be applied over a clean, dry, sealed floor for extra protection and shine. Weekly damp mopping with a barely damp mop on a waxed floor will keep it clean for quite a while before the washing with detergent is needed.
If you have an electric polisher, solvent-based polishing wax may be used to clean and wax. This must be buffed. Do not use wax around fireplaces.