trachytic

enUK

tra·chyte

T0300200 (trā′kīt′, trăk′īt′)n. A light-colored igneous rock consisting essentially of alkali feldspar.
[French, from Greek trākhus, rough.]
tra·chyt′ic (trə-kĭt′ĭk) adj.

trachytic

(trəˈkɪtɪk) adj (Geological Science) (of the texture of certain igneous rocks) characterized by a parallel arrangement of crystals, which mark the flow of the lava when still molten