Transmitted Crossed Linear Polarized Light
Significance in the Environment:
This is a common clothing fiber.
Hemp has a refractive index along its length of about 1.58 to 1.59 and perpendicular to its length of about 1.53 to 1.54.
It has a birefringence of up to 0.05 and a positive sign of elongation.
DuPont Company Techinical Bulletin X-156: IDENTIFICATION OF FIBERS IN TEXTILE MATERIALS, December 1961.