Thanks so much! :D I've been wantign to work on mineral characterization videos for a while. I'm hoping to start work on them this summer - stay tuned!

As polarized light passes through an anisotropic medium, light splits into a fast and slow component that vibrate perpendicular to each other. Inserting a cross-polarizing filter (aka the analyzer) between your sample and your eye recombines (think vector addition) the fast and slow waves of light by only allowing one vibrating direction through. Check out figure 3 in this write-up by Olympus: www.olympus-lifescience.com/en/microscope-resource/primer/lightandcolor/birefringence/ Hope this helps! Happy Microscoping :D

Hi! Although I'm not too familiar with liquid crystal properties, you can always calculate birefringence by the relationship: Retardation = thickness x birefringence. You can determine the retardation by noting the interference color you observe and referring to the bottom x-axis on a Michel-Levy. Since you know your thickness, you can solve for birefringence.

Thanks for watching! Although I try to speak slowly and clearly, it's still a challenge to narrate these videos after growing up with a pretty heavy Staten Island accent. :D You can always turn on the closed captioning (CC) to help with parts of the video where the narration is unclear. Happy flash figuring!

Thanks for watching! Happy mineralogy-ing! :D

Thank you for watching and sharing!

Great question Nathan! Short answer is yes. If you know the mineral you are looking at, and record the birefringence of your sample, you can use the Michel-Levy chart to roughly determine the thickness. To more precisely measure thicknesses of objects in thin section (minerals, melt/fluid inclusions, bubbles, etc.), I prefer to use a microscope with a calibrated focus knob. For this method, I put the top of the object in focus, take note of the measurement on the focus knob, turn the knob to put the bottom of the object in focus, and take note of the new measurement on the focus knob. The thickness of your object is the difference between the two measurements. I hope this helps - please let me know if it is unclear or if you have questions. This sounds like a good idea for a new video... :)

@@EarthOpticsVideos Thank you very much for your reply. Your explanation is very clear, and I will deffinatly test out both of those methods.