Augite, subcalcic augite, and pigeonite lie within the interior of the pyroxene quadrilateral Compositionally, augite is related to members of the diopsidehedenbergite series with limited substitution of Na for Ca 2 , Al 3 for Mg 2 and Fe 2 , and Al 3 for Si 4 in the Z(tetrahedral) siteAugite (pyroxene) 6 dark green to black gray vitreous YES 2 dir at nearly 90 o complex silicate Most common pyroxene;In case a) augite is formed parallel to the (001) plane of pigeonite, but the augite is not exsolved by the pigeonite This is proved by the absence of the obligatory streaks between corresponding reflections in highly resolved precession photographs Instead, there are streaks from augite to the corresponding reflections of the host orthopyroxene
Pyroxene The Pyroxenes Are A Group Of Common And Important Ca Mg And Fe Bearing Silicate Minerals There Are Dozens Of Specific Minerals In The Pyroxene Group These Include Augite Diopside Hedenbergite Pigeonite Enstatite Bronzite
