Laser-induced time-resolved luminescence of natural sillimanite Al2SiO5 and synthetic Al2SiO5 activated by chromium

Luminescence of natural sillimanite Al2SiO5 was studied by a laser-induced time-resolved technique combined with absorption spectroscopy. It was found that two red broad emission bands are connected to Fe3+ and Cr3+ luminescence centers. Chromium participation in luminescence was proved by the study of synthetic sillimanite activated by Cr. Several narrow emission lines have been found which were preliminary ascribed to Mn4+ and V2+ luminescence centers.