![6.6 Orbicular hornblende-augite granodiorite. Davie County, North Carolina. Orbs consist of quartz-epidote cores rimmed by augite (lighter, duller green) and hornblende (dark green to black) in a matrix of gray to white, glassy quartz and white to orange-white alkali feldspar with a few small white grains of plagioclase feldspar. Titanite and orange-iron oxide minerals occur in some orb centers. Titanite occurs as adamantine, yellow to brown crystals (e.g., upper left and mid-right). Nearly invisible are yellow to light red, needle-like grains of rutile within feldspars. [Scale is standard GSA scale with cm divisions.] Commonly, in outcrop, plagioclase dominates over alkali feldspar, so that such rocks are quartz diorites.](../6.6.JPG)
6.6 Orbicular hornblende-augite granodiorite. Davie County, North Carolina. Orbs consist of quartz-epidote cores rimmed by augite (lighter, duller green) and hornblende (dark green to black) in a matrix of gray to white, glassy quartz and white to orange-white alkali feldspar with a few small white grains of plagioclase feldspar. Titanite and orange-iron oxide minerals occur in some orb centers. Titanite occurs as adamantine, yellow to brown crystals (e.g., upper left and mid-right). Nearly invisible are yellow to light red, needle-like grains of rutile within feldspars. [Scale is standard GSA scale with cm divisions.] Commonly, in outcrop, plagioclase dominates over alkali feldspar, so that such rocks are quartz diorites.