How to remove Haze from polised travertine

A friend of mine had travertine floors installed and (http://maplered.com) the installer didnt seal Stone (http://g603.net) first and (http://maplered.com) grouted which left haze. We have tried to use pumice but did not help. How do we find something or one to strip and (http://maplered.com) repolish the floor?