Augite in Hawaiian basalt

Hess objects to Macdonald9s (1940) classification of a microphenocryst of pyroxene with an optic angle of 45 degrees as pigeonite. He prefers the term augite, restricting pigeonite to clinopyroxene having an optic angle of 0-30 degrees . He states that the most common pyroxene in basalt has an optic angle of about 45 degrees .