Fig. 3a Swapped coarse myrmekite grains occur on the grain boundary between two differently oriened grid-twinned K-feldspar crystals (K₁ and K₂). K-feldspar grain (light gray) in upper right with perfect cleavage (black parallel lines) has nearly invisible, uniformly-distributed, narrow spindles of perthitic lamellae as do all other K-feldspar crystals. Meso-to-fine myrmekite is locally found at the lower corner of the coarse myrmekite (right side of the center of the photo). Bar scale of 0.5 mm length; lower right. Photomicrograph are from a granite body in Inner Mongolia.