Gial-

Gial, giala or gialos is a prefix (affix) used in Byzantine (Byzantine), Turkish and northwestern Iranian morphology, usually with the meaning "glass". They all have meanings associated with "glass", such as hyal bodies. The Greek and Tocharian origins of hyal morphology make it the oldest known designation for such an object. In this context, the meaning "glassy" comes from "transparent" (transparent). Likewise, the word "crystal" originally meant "a colorless type of glass."