|Alexandrite section from Bahia, Brazil (~0.5mm
thickness). This picture and the following illustrate the beautiful
pleochroism from green to yellow to pink of the Alexandrite.
The spectra below were recorded on the green-pink and yellow-pink
parts of the crystal changing the orientaion of the polarizer by 90°.
The presence of Cr3+ ions in the chrysoberyl structure gives
the bimodal absorption feature responsible for the color and the