how to get smoother travertine?

hi, our contractor purchased honed and (http://maplered.com) filled travertine for our kitchen and (http://maplered.com) bathrooms. it looks very nice, but is not as smooth as i would like, or have seen it in certain installations. was wondering if there is a way to get it smoother? shoudl i ask our contractor to sand (http://maplered.com) or buff it? or would a sealer be sufficient to make it smoother?