Geometric patterns of fluorescence in diamond

Summary

The blue and yellow patterns of luminescence exhibited by 19 cleavage plates of diamond have been photographed separately using appropriate light filters, and are reproduced along with the patterns of transparency of the same plates to the λ 2536 radiation of the mercury arc and their birefringence patterns. Study and intercomparison of the patterns enables the correlations between luminescence, ultraviolet transparency and birefringence to be readily perceived and interpreted with reference to the structure of the crystal. The blue and yellow patterns are often strikingly different. In some cases, they both appear as parallel bands, but running in different directions through the crystal.