The wood has been sealed with a marine varnish that protects it from water and other liquids. The sealer is used, as it suggests, in the marine industry to seal wood boat decks, railings, etc. from water and UV damage making it an ideal finish for wood countertops.
This beautiful walnut counter and island combo are part of a basement remodel in the Atlanta area. Lots of great room for seating, serving and playing games.