Well, that certainly is interesting. Although the Crewniverse has said that Peridot's weapon is her gem technology and Lapis' weapon is her water wings, it's probably safe to assume that Sapphire's weapon is her future vision. It's not a physical weapon, but it is definitely an ability that has been shown to be unique to herself and, at the very least, to Garnet (it is never revealed whether or not Sugilite or Sardonyx posses future vision). We've seen Ruby and Garnet both use gauntlets, although Garnet's definitely differ in style from Rubys. So, what do you think?