phen·gite \ˈfenˌjīt\noun (-s) Etymology: German phengit, from Latin phengites, from Greek, from phengos light, moonlight + -itēs -ite 1.: a transparent or translucent stone prob. selenite or crystallized gypsum used by the ancients for windows 2.: a variety of muscovite with substitution of aluminum for magnesium and silicon • phen·git·ic\(ˈ)fen|jid.ik\adjective