Sapphires, topaz, emeralds, rubies, garnets, morganites, moissanites, tourmalines, zircons, peridots, citrines, moonstones, spinels, alexandrites, and onyxes are all very good stones for rings!
You would have to be more careful when dealing with amethysts, tanzanites, turquoise, lapis lazuli (you can't get water on these by the way, they produce toxins), and pearls as they can scratch easily and aren't very hard.