Fig. 7a. Swapped nibble metasomatic K-feldspar crystals (K₁', K₂') occur on the contact between two primary K-feldspars (K₁, K₂) in Hengling pyroxene monzonite, Guangdong province, southern China. Cross-polarized light with a quartz plate. Pyroxene (dark fractured grains with high relief); plagioclase (Pl, cream). Scale bar = 1 mm.