Optical Mineralogy - Optical Indicatrix, Uniaxial vs Biaxial, Interference Figures - GEO GIRL

Dive into the world of optical mineralogy with this comprehensive video lecture on the optical indicatrix, uniaxial vs biaxial minerals, and interference figures. Learn how to use the optical indicatrix and its properties to identify minerals, understand the impact of mineral grain orientation on optical properties, and explore the use of special lenses like the upper swing-in condensing lens and Bertrand lens in petrographic microscopes. Discover how to determine optic axes, optic angles, optic signs, and interference figures for mineral identification. Gain insights into uniaxial and biaxial minerals, their interference figures, and how to determine their optic signs. Conclude with a review of diagnostic properties for mineral identification and a preview of upcoming content in the mineralogy playlist.

Review & what this video will cover
How crystal system affects optical properties of minerals
Intro to optical indicatrix
The uniaxial optical indicatrix
Uniaxial optic axis
The biaxial indicatrix and optic axes
Biaxial optic angle and optic sign
How to apply this to minerals under thin section?
Bertrand lens & condensing lens
Uniaxial interference figures
Uniaxial flash figures
How to determine optic sign of uniaxial minerals
Biaxial interference figures
Biaxial optic angle or 2V angle
Acute bisectrix figure & obtuse bisectrix figures
Biaxial optic sign
Review mineral identification chart
Upcoming content & NEW PLAYLIST!
Bloopers!