Nope. Unfortunately the only Gem that is obtainable at the moment is the Normal Gem, as the others cannot be found anywhere and items can't be transferred via Pokemon Bank. If you are interested in a Normal Gem, you can find them in Terminus Cave.
However, I do feel that they will make an appearance eventually. Game Freak really aren't the type to introduce a group of popular items and then abandon them a few years later.
