If you're still on the search for your engagement ring, why not consider something a little different. While it is traditional for a groom-to-be to present his beloved with a ring featuring diamonds, many couples now choose the ring together. And nowadays, a diamond is not always the featured stone. Even some of the most traditional people in the world stray from the norm in the case of engagement rings. Royals the world over are trading white diamonds for truly inspiring gem choices. Take Princess Diana's engagement ring, which now happily resides on the ring of Kate, Duchess of Cambridge….