The article informs that in minerology, dichroism is the phenomenon in which a crystal has two different colors when viewed along different crystal axes (dichroism = "two-colored"). Circular polarized light is useful in spectroscopy because in some circumstances, right-circularly polarized light is absorbed in different amounts than left-circularly polarized light. This differential in absorption of circular polarized light gives rise to dichroism spectroscopy. Chiral molecules rotate the plane of linearly polarized light because they absorb preferentially either left-circularly or right-circularly polarized light.
Ball, David W., "Dichroism Spectroscopy" (2004). Chemistry Faculty Publications. 124.