pa·lag·o·nite 
(pə-lăgə-nīt′)
(pə-lăgə-nīt′)n.
A brown, yellow, or orange volcanic glass that is interstitial material in pillow lava or in amygdules and is formed through the hydration of tachylyte.
[German Palagonit, after Palagonia, municipality in southern Sicily where it is found.]
pa·lag′o·nitic (-nĭtĭk) adj.