Fig. 4. Replacement of plagioclase (tan; albite-twinned; bottom) by microcline (grid-twinned; dark gray) from border and interior of plagioclase crystal in granodiorite. Note irregular islands of microcline in plagioclase with albite-twinning of the grid-twinning parallel to albite-twinning in plagioclase. Note remnant islands of plagioclase (top) in optical parallel alignment with larger plagioclase crystal at the bottom. Biotite (lower right corner; brown).