Fig. 1. Sapphires from Sri Lanka (a) and Laos (b)

Fig. 2. UV-Vis-NIR spectra of Sri Lanka sapphires (a) and Laos sapphires (b)

Fig. 3. Fluorescence reaction under LW-UV and SW-UV of Sri Lanka sapphires

Fig. 4. Three-dimensional fluorescence spectra of metamorphic-type sapphires from Sri Lanka

Fig. 5. Emission fluorescence spectra excited by (a) 320 nm, (b) 360 nm, (c) 410 nm, (d) 450 nm of metamorphic-type sapphires from Sri Lanka

Fig. 6. Three-dimensional fluorescence spectra of basalt-related-type sapphires from Laos

Fig. 7. Emission fluorescence spectra excited by 360 nm of basalt-related-type sapphires from Laos