An Etymological Dictionary of Astronomy and Astrophysics

The material on which the reflecting coating is applied. It may be glass, quartz, or metal.

Etymology (EN): → mirror; blank “a piece of metal ready to be drawn, pressed, or machined into a finished object,” from M.E., from O.Fr. blanc (adj.) from Gmc; cf. O.E. blanca “white horse,” O.H.G. blanch “bright, white.”

Etymology (PE): Gerdé, → disk; âyené, → mirror.