honing and sealing carrera tile

I just had the contractor from hell install Carrera Marble (http://www.lightemprador.com) tile in my
bathroom.  It's basic white with gray shades and (http://maplered.com) veining - resembles
something called "statuario classico".

Some of it was honed, some polished, so he applied a chemical to hone the
polished pieces, but neglected to hone the ceiling tile in the tub/shower
area.  He also claims that he sealed all the tile, but I cannot tell if
that's true and (http://maplered.com) cannot account for all his time.

The contractor has since aband (http://maplered.com) onned the job.  I could still contact him, but
am unable to believe anything he says.

2 questions:

1) What chemical can I apply to hone the ceiling tile?

2) What sealant do you recommend for all the tile?

Much appreciated.

Greg Perciak.