Fig. 5. Grid-twinned K-feldspar (upper left), myrmekite (dark blue) with quartz vermicules (light blue), and quartz (clear blue, lower right). Because myrmekite is relatively large (with a width greater than 1.5 mm), the mineral (likely K-feldspar) on which the myrmekite grew naturally may not appear together with the myrmekite in one thin section which is only 0.03 mm thick Bar scale of 0.5 mm length; lower right. Photomicrograph is from Guangshigou pegmatoid granite, South Shaanxi Province.