When are they going to get around to making transparent aluminum?
http://www.tssbulletproof.com/optically-clear-aluminum-provides-bulletproof-protection/
Been there, done that.
Either Magnesium Aluminate Spinel or Aluminum Oxynitride?
http://www.wideopenspaces.com/50-caliber-armor-piercing-bullet-vs-surmets-alon-transparent-armor-video/