Fig. 2. This photomicrograph shows a portion of a microcline megacryst (black, left side) with irregular, non-uniformly distributed albite lamellae in perthitic intergrowths (light gray) in Kinsman granodiorite in New Hampshire (USA). Coarseness of quartz vermicules in bordering myrmekite suggest that the K-feldspar replaced a former diorite. Note that vertical albite twins in plagioclase are bent and broken (dark gray, right side), and locally K-feldspar (light gray) has replaced the plagioclase along a fracture. Field relationships support a magmatic origin for the Kinsman pluton because dikes from this pluton extend into the country rock. The maximum size of quartz vermicules in the myrmekite suggests, however, that this pluton was a former magmatic intrusive diorite that was later deformed and replaced by K-bearing fluids to create the K-feldspar megacrysts (as much as 4 cm long).