313964d8_Microscopy__Determinative_value
[Optical property] Refractive indices [Measurement] Orientation of principal vibration direction with polarizer of microscope. Matching of two (uniaxial crystals) or three (biaxial crystals with index of refraction oils. [Determinative value] 
Crystallographic identification of chemical crystals and minerals. Identification and comparison of artificial fibers.
Microscopy
Determinative value