Definition of acute bisectrix

Photonics Dictionary

acute bisectrix: The term acute bisectrix is used in mineralogy and crystallography to describe a specific optical property of minerals, particularly in relation to their crystal structure and light behavior.

In optical mineralogy, the acute bisectrix refers to one of the three principal optical axes within a crystal of a biaxial mineral. Biaxial minerals are those that exhibit double refraction and have two optic axes (fast and slow) with different refractive indices.

Principal optical axes:

Optic axes: Biaxial minerals have two optic axes where light travels with different velocities (refractive indices) along different directions through the crystal.

Acute bisectrix: This term specifically refers to the direction within the crystal where the angle between the fast and slow optic axes is acute, meaning less than 90 degrees.

Characteristics:

Birefringence: Biaxial minerals exhibit birefringence, where light passing through the crystal splits into two rays with different refractive indices, resulting in double refraction.

Optical sign: The nature of the acute bisectrix (positive or negative) indicates the relationship between the refractive indices and their orientation within the crystal structure.

Measurement and use: Identification and characterization of the acute bisectrix are essential in mineral identification using polarized light microscopy and other optical techniques. It helps determine the crystallographic properties and orientation of the mineral.

Applications: Understanding the optical properties of minerals, including the location and nature of the acute bisectrix, is crucial in fields such as geology, mineralogy, gemology, and materials science for mineral identification, classification, and study of geological processes.

PowerPhotonic Ltd. - Bessel Beam Generator MR 6/24

COMSOL Inc. - Find Your Best Idea MR 12/24