Tephriphonolite
Tephriphonolite is a mafic to intermediate extrusive igneous rock in composition between phonotephrite and phonolite. It contains 9 to 14% alkali content and 48 to 57% silica content.
Tephriphonolite has been found, for example, at Colli Albani volcano in Italy and in the Asunción Rift of Paraguay.
