trachyte

noun

1. a fine-grained volcanic rock consisting essentially of alkali feldspar and one or more subordinate minerals, as hornblende or mica: the extrusive equivalent of syenite.

noun

1. a light-coloured fine-grained volcanic rock of rough texture consisting of feldspars with small amounts of pyroxene or amphibole

1. A light-colored, fine-grained igneous rock consisting primarily of alkali feldspar together with some mafic minerals, especially hornblende. Unlike most igneous rocks, trachyte has little or no quartz. Trachyte is the fine-grained equivalent of syenite.