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Photographic gallery.  Thousands of particles under the microscope.

Feather, Cat Hair, and Mercerized Cotton

Transmitted Cross Polarized Light Illumination

The top, bright short fiber is mercerized cotton fiber with a red dye. The fiber below it is the cat hair. The bottom fiber is a bird feather barbule. This image shows the relative "brightness" of the retardation effect for these different types of fibers.