Luminescence and a New Approach for Detecting Heat Treatment of Sapphire

Autor(en)
T. Pluthametwisute, L. Nasdala, C. Chanmuang N., M. Wildner, E. Libowitzky, G. Giester, G. Zoysa, C. Jakkawanvibul, W. Suwanmanee, T. Sripoonjan, B. Wanthanachaisaeng, T. Sripoonjan, T. Tengchaisri, B. Wanthanchaisaeng, C. Sutthirat
Abstrakt

For decades, unravelling heat treatment of sapphire has been a challenging issue. The present study offers new aspects that support the detection of heat treatment of sapphire. Natural unheated sapphire is distinguishable from heated sapphire by its orange to red luminescence under long-wave ultraviolet (LWUV, 365 nm) light, whereas blue luminescence under short-wave ultraviolet (SWUV, 254 nm) light indicates their heated counterparts. UV-excited photoluminescence shows a linkage between a broad emission spectrum within the orange to red region and orange to red luminescence of natural unheated sapphire under LWUV illumination, as well as an emission spectrum around the green region and blue luminescence of heated sapphire under SWUV illumination. Furthermore, the presence of melt inclusions within dissolved silks may be used as an indicator of heat treatment of sapphire. It seems that Fourier-transform infrared (FTIR) spectroscopy alone is inadequate for distinguishing unheated and heated sapphire. The application of orange to red, and blue luminescence together with melt inclusions offer a novel and practicable procedure for more precise differentiation of unheated versus heated sapphire.

Organisation(en)
Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Chulalongkorn University, Mincraft Company, Gem and Jewelry Institute of Thailand, Chiang Mai University, Burapha University
Journal
EGUsphere : the EGU interactive community platform : the preprint repository of the EGU
Band
2024
DOI
https://doi.org/10.5194/egusphere-2024-1529
Publikationsdatum
09-2025
Peer-reviewed
Ja
ÖFOS 2012
105116 Mineralogie, 105113 Kristallographie, 104026 Spektroskopie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/e0701c97-3545-4c3e-8f99-542c21ceb6e7