1. Laser-induced breakdown spectroscopy for gemological testing / Francesco Poggialini, Beatrice Campanella, Stefano Legnaioli, Simona Raneri and Vincenzo Palleschi
2. Raman spectroscopy for the non-destructive analysis of gemstones / Danilo Bersani, Laura Fornasini, Peter Vandenabeele and Anastasia Rousaki
3. Application of Fourier-transformed infrared spectroscopy and machine learning algorithm for gem identification / Pimthong Thongnopkun, Kanet Wongravee, Prompong Pienpinijtham and Aumaparn Phlayrahan
4. A ruby stone grading inspection using an optical tomography system / Syarfa Najihah Raisin, Juliza Jamaludin and Fatinah Mohd Rahalim
5. Trace elements and big data application to gemology by x-ray fluorescence / Yujie Gao, Moqing Lin, Xu Li and Xueying Sun.