yes!! with a black dress, you can wear practically anything. ruby and diamonds sound beautiful!
I wouldn’t, but that shouldn’t matter. Go for what you like. Be the person you want to be, yourself, and knock-em-dead.
Try them on, and if you think it looks good, go for it.
My opinion, for what it is worth, is that white/silver works best with black. Diamond or pearl studs, preferably on silver/white gold settings. or small silver (or white gold) hoops or short drops would go best. Just don’t overdo it with massive whore hoops. Small is sexy, big is slutty.