The nature of red luminescence of natural benitoite BaTiSi₃ O₉

This work examines the red luminescence of benitoite studied by laser-induced time-resolved luminescence spectroscopy. This method allows the differentiation between luminescence centers of similar emission wavelengths, but different decay times. We have also examined the luminescence intensity and decay time as a function of temperature. We found that the red emission of benitoite consists of two individual bands and one line and suggest that the activators of luminescence in benitoite system are Ti³⁺ and a d³ element, namely Cr³⁺ or Mn⁴⁺.