Fig. 4c. The same part of Fig. 4a. Under cross-polarized light with quartz plate inserted. Swapped replacing K-feldspar crystals (K₁', K₂') occur at the grain boundary between two differently oriented primary K-feldspar crystals (K₁, K₂) with a few albite lamellae (Ab₁. Ab₂). K₁' replacing K₂ in front takes the same orientation as the primary K-feldspar K₁ at the back. So does K₂'. K₁' and K₂' are characterized by the presence of vermicular perthitic stringers (Ab₁' and Ab₂') that are absent in primary K-feldspar (K₁, K₂) and remnants of albite lamellae (Ab₁, Ab₂) of the primary K-feldspar (K₁, K₂) being replaced. Scale bar = 0.5 mm.