Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† phengītes, ae, m., = φεγγίτης, phengite, selenite, or erystallized gypsum, used for window-panes: in Cappadociā repertus est lapis candidus, atque translucens, ex argumento phengites appellatus, Plin. 36, 22, 46, § 163; lapis, Suet. Dom. 14.