An optical effect in which the amount of plane polarized light reflected from a mineral sample varies as the sample is rotated.

How would you describe pleochroism?

Pleochroism is the term used to describe the color variation for destructive interference with the polarization direction of the light, which depends on the orientation of the material in the light path and is a characteristic of anisotropic materials only.

What is pleochroism in thin section?

1. An optical property found in many minerals in which a crystal is able to absorb different wavelengths of transmitted light depending on the orientation of the crystal. 2. A useful characteristic for identifying minerals in thin section with an optical microscope.