This first picture shows part of the pattern. It's four different sized pieces but the repeating pattern is ten. The floor was re-inforced then mudded.

This second picture shows the grout line. The tiles are actually touching under the grout. You can't get a smaller grout line with this type of stone tile because the edge of each tile is rounded. The grout fills in that space.

lagrant-- if your tiles have a slight chamfer to the top edges, he'll be able to sett the tiles 1/16" apart, but it's going to SHOW an 1/8" joint, due to that chamfer. Ask him if that's what he's talking about. If, however, the tiles DON'T have that little chamfer, then yes, they can be set with a 1/16" joint. If an 1/8" joint IS used in that case, then yes, it should be sanded grout.

We have 16x24 limestone on our floor with a 1/16" joint. The edges of the limestone are slightly eased. We went with a staggered layout and love the way it turned out.

Here is a picture: