1. The structure of amethyst quartz and the origin of its pleochroism

   • C. V. Raman
   • A. Jayaraman

   OriginalPaper Pages: 189 - 195

2. On the pleochroism of amethyst quartz and its absorption spectra

   • S. Pancharatnam

   OriginalPaper Pages: 196 - 210

3. The Raman spectrum of diamond

   • D. Krishnamurti

   OriginalPaper Pages: 211 - 216

4. Some illustrations of the optical behaviour of iridescent calcite

   • A. K. Ramdas

   OriginalPaper Pages: 217 - 219