If you don't have a ring-blade tile saw and you need to cut a curve in a natural-stone tile, master tilesetter Tom Meehan has some good news and some bad news. The good news is that the job is not impossible, cutting the outside radius is relatively easy, and the bad news isn't so bad. To cut the inside radius, you need to make a series of small, careful cuts on the saw while holding the tile firmly and square. The final steps include using a grinder as you would a glass cutter and bringing the curve home with the help of nippers. It takes a little more effort than the alternative, but the results, if done properly, are identical.
Interested in the alternative? Watch Tom demonstrate how he cuts tile with his Revolution XT ring-blade tile saw. And, to learn how Tom used the tiles he cut in the video for a shower he built, read Glass-Block Shower on a Curve from Fine Homebuilding issue #200 (December 2008/January 2009), pp. 58-61.