I recently completed a final exploring the refractive properties, patterns, and color of polarized crystals.

Polarized light is light that has waves oscillating all in the same direction. The first polarizing sheet, or the polarizer, goes on top of the substage illuminator. The second polarizer or analyzer goes on the camera port. The sample is placed on a slide on the stage between the two polarizers. This method reveals internal stress patterns of objects that are invisible to the naked eye. A sheet of Mylar over the bottom polarizer to alter the color variations.
Images were captured using an Olympus BX40 and a Canon R5 tethered to Capture One.
The microscope was set for Köhler illumination with no other lights on in the room.