Fig. 29.-Nonuniform sericitization of plagioclase (Pl,
An20-25)
Microprobe
analysis shows that the sericitized plagioclase (points 4, 5, 6) is transformed
to albite (An2-4). The unsericitized plagioclase (points 1, 2, 3)
maintains primary constituent (An20-25, without clear albite
twinning), where the small patches of K-feldspar with very low interference
color is still preserved (point 7). Crossed polars. Jiling granite,