Eleanor Day It's either travertine or a really good porcelain tile made to look like travertine. I personally prefer a porcelain tile in a wet area. Real stone can degrade over time and is hard to keep clean, especially in humid climates.
See this mini 5/5" mosaic in the niche and on the floor... I saw something like this on a backsplash when I was watching HGTV the other day with white cabinets and it was GORGEOUS!!!