MineralogyPhonolite is an uncommon extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grained) to porphyritic (mixed fine- and coarse-grained). Its intrusive equivalent is nepheline syenite.
Contentnepheline, sodalite, hauyne, leucite, analcite, sanidine, anorthoclase
Secondary biotite, amphibole, pyroxene, olivine.