Tephriphonolite or tephri-phonolite is a mafic to intermediate extrusive igneous rock in composition between phonotephrite and phonolite.[1] It contains 9 to 14% alkali content and 48 to 57% silica content (see TAS diagram).[2] Tephriphonolite is roughly equivalent to tephritic phonolite of the QAPF classification.[3]
Tephriphonolite has been found, for example, at Colli Albani volcano in Italy[4] and in the Asunción Rift of Paraguay.[5]