Luminescence and a new approach for detecting heat treatment of geuda sapphire
- Author(s)
- Teerarat Pluthametwisute, Lutz Nasdala, Chutimun Chanmuang N., Manfred Wildner, Eugen Libowitzky, Gerald Giester, E. Gamini Zoysa, Chanenkant Jakkawanvibul, Waratchanok Suwanmanee, Tasnara Sripoonjan, Thanyaporn Tengchaisri, Bhuwadol Wanthanchaisaeng, Chakkaphan Sutthirat
- Abstract
For decades, unraveling the 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 geuda sapphire exhibits orange to red luminescence under longwave ultraviolet (LWUV; 365 nm) light, while heated geuda sapphire shows blue luminescence under shortwave ultraviolet (SWUV; 225 nm) light. The presence of melt inclusions in dissolved silks serves as an indicator of sapphire heat treatment. Fourier-transform infrared (FTIR) spectroscopy alone is insufficient for distinguishing unheated from heated sapphire. By combining orange to red luminescence with blue luminescence and melt inclusions, we provide a practical method for accurately differentiating natural gem-quality sapphire and heated gem-quality sapphire.
- Organisation(s)
- Department of Mineralogy and Crystallography
- External organisation(s)
- Chulalongkorn University, Mincraft Company, Gem and Jewelry Institute of Thailand, Chiang Mai University, Burapha University
- Journal
- Solid earth
- Volume
- 16
- Pages
- 81-96
- No. of pages
- 16
- ISSN
- 1869-9510
- DOI
- https://doi.org/10.5194/se-16-81-2025
- Publication date
- 01-2025
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105116 Mineralogy, 105113 Crystallography, 104026 Spectroscopy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/e0701c97-3545-4c3e-8f99-542c21ceb6e7