Stones like Turquoise, Coral, Opal, Jasper, Onyx, Lapis, Sodalite, Larimar, Jasper, Agate and Malachite are commonly used in. The design of the ring will affect how it fits as well. If the ring is solid and wide it might fit more like the next size down.
This product would be a great fit for those seeking a unique statement ring with a blend of sterling silver, blue turquoise, and a fan pattern.