Fig. 4. Tiny orthoclase crystal (light gray), replacing plagioclase (black, right and left sides; gray, bottom). Orthoclase forms wedges and scalloped boundaries against the plagioclase. Myrmekite with very tiny quartz vermicules (left side of orthoclase) forms a border against the plagioclase. Quartz (tannish gray; lower center); muscovite (brightly colored grains).