Looks like marble...

Looks like carrara white marble was used for the subway tiles, base and chair rail and weave mosaic for the floor - not sure on the black accent around floor and the pencil below the chair rail.

Walker Zanger shows the marble tiles in its catalog

Carrara marble honed. Color varies depending on each box. Some can look less/more gray. You never know with marble.

I am the designer of this bathroom. All of the tile is natural marble from Walker Zanger's Tribeca Collection. The wall tile is called 2x8 Classic White; marble base is 5x12 Boulevard Base Molding in Classic White; mosaic border is 1/2" Flatiron Grey Mosaic Field Tile; top chairrail is 2x12 Mercer Molding. This is from the 2008 Junior League Decorator Showhouse in Montgomery, AL. Not sure if they still make the tile, but I hope this helps! You can see other pics of the bathroom if you "like" my facebook page: Plush Design Studio (Montgomery, AL) or my website will be up in about a week: www.plush-design-studio.com.