These look great on my shower floor and waterfall feature.  I would advise to buy about 25% extra so you can choose the best looking ones, they are very random (and inexpensive, so it's not a big deal).  Before installation, either seal them with enhancer (most helpful), or at least wet them so you can see what they will look like after installation.  Some stones were noticeably thicker than my tile so I had the installers take that in to account for the vertical waterfall feature (to appear flush with the tile).