Liparite

Liparite, an igneous rock, so called from its occurrence in the island of Lipari. It has a wide geographical distribution, and is also known as Rhyolite and Quartz-trachyte. It is a highly acidic rock, and has a glassy base, often more or less devitrified. Throughout this base are scattered quartz, sanidine, plagioclase, and biotite; and other minerals may also be present. The more compact varieties often exhibit sphenelitic and fluxion structures, which occasionally impart a kind of laminated or banded aspect to the rock. Other varieties of texture range from compact up to coarse-grained and granitoid.