Fig. 3. Photomicrograph of Sjelset charnockite showing albite-twinned plagioclase (black and white, lower left), orthoclase (gray), and quartz (cream, white). Myrmekite with circular to oval cross-sections of coarse quartz vermicules (white to gray) is in lower right. Orthoclase (top) appears to surround a broken fragment of a plagioclase crystal because of the nearly perfect alignment of albite-twin lamellae. Fragments of the albite-twinned plagioclase (lower left) extend upward into the orthoclase.