Below are images of various tile color / designs that I use in my medallions and backsplashes. In addition, many of the tiles that are commonly available through national tile stores and the home improvement stores (Home Depot and Lowes) may be used in a medallion or backsplash.
Please note: Some tiles types, however, do not work as well for use in medallions and back splashes. Some granites, for example, are more likely to fracture. Many travertine tiles are highly pitted and not well filled. And some ceramics and porcelains are more prone to chipping when being cut. I have found that the tile options below work well when used in medallions and back splashes.
*See my About Travertine informational page