Uniaxial Systems
It contains <omega>.
Circular Section
Angle between Optic Axes
2V
Pattern of black bands
Isogyre
Mineral with uniform physical properties, including a single refractive index, because its crystal structure is the same in all directions
Isotropic
Maximum displacement measured from equilibrium position
Amplitude
It contains <epsilon> and <omega>
Principal Section
Shape of isochromes in biaxial minerals
Teardrop shaped
One optic axis is vertical, and correspondingly the second optic axis and the bxa are inclined to vertical.
Centered Optic Axes Figure
Minerals that show the property of double refraction
Anisotropic
lineal distance between successive wave crests
In this interference figure the Optic Axis is vertical
Optic Axis Figure
Crystal System - indicatrix axes coincide with crystallographic axes
Orthorhombic
Bxa and Bxo parallel to the polarization directions, isogyres form a broad fuzzy cross, with only
the outer edges of each quadrant allowing any light to pass
Optic Normal Figure
Abstraction of the optical properties of minerals
Optical Indicatrix
Absorption properties
Color, Pleochroism
In this interference figure the Optic Axis is horizontal
Flash Figure
Crystal System - Y axis of indicatrix coincides with one of the crystallographic axes
Monoclinic
Method that uses an acute bisectrix figure to calculate the angle between optic axes
Mallard
Range of polychromatic light
300nm - 700nm
Refraction properties
Relief, Becke Lines
Off-centered Optic Axis Figure - this ray is radial from the melatope
Extraordinary ray
Crystal System - none of the indicatrix axes coincide with crystallographic axes
Triclinic
Method that involves measuring the angle of stage rotation needed to cause the cross shaped isogyre in the acute bisectrix figure to split apart and leave the field of view
Kamb
Central ray of the cone of light hits perpendicularly; the rest of the rays coming out of the cone propagate along different crystallographic directions in the crystal.
Conoscopic Light
The point where the optic axis emerges in the interference figure
Melatope