Skin Flakes and Clothing Fiber
The clothing fiber (cotton above and rayon below) is easily seen in this tapelift from a home by its birefingence.
The human skin flake is the faint, isotropic, more equant, colorless particle at the upper center of the right margin of this image. The
rounded particle to the left of the skin flake is a hydrated starch particle. The typical cross patern of the starch grain is absent because of
the use of circular polarized light.
Transmitted Oblique Off Crossed Circular Polarized Light Illumination
Significance in the Environment:
Human dander varies from isotropic to particles with stress birefringence. The stress birefringence of human skin flakes tends to be low. The
refractive index of human skin flakes tends to be around 1.550 but will vary with stress and oil content.