Travertine bathroom Counter (http://GialloFiorito.com) needs holes sealed ??

I had a Travertine Counter (http://GialloFiorito.com) and (http://maplered.com) an undermount sink "professionally" installed for my master bathroom. The travertine had to be cut for the hole where the undermount sink would be placed. All around the hole are these gaping holes that seem to get bigger as I wipe down the dust from the initial installation. I went to my local hardware store who suggested some kind of epoxy filler to smooth the surface and (http://maplered.com) THEN seal it. I need advise before I am left balancing my bathroom sink on one hand (http://maplered.com) while washing my face with the other.