Uniaxial Birefringence

Uniaxial Birefringence: Minerals crystallizing in the Hexagonal, Trigonal, and Tetragonal Crystallographic Systems, all of which are Birefringent, exhibit the specific property of conveying a light ray penetrated into them in a direction (direction of Monorefringence, called Optical Axis when Birefringent stones are concerned) in which the ray is neither split at a differential speediness transmission nor polarized, thus behaving (in that direction) as in a Monorefringent substance.

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