The 010 section of monoclinic mineral necessarily shows

(001) face will also show inclined extinction in monoclinic. Only (100) face will show parallel extinction in monoclinic minerals.

(010) face of monoclinic crystal shows inclined extinction. Only if the (100) face is parallel to the stage will parallel extinction be observed.

This is a section Cut the b axis so the vibration direction is not parallel to the axis . So inclined Extinction. Basal section (001) and Ortho section (Cut the a axis and para...