[2] Sun Z, Palke A, Muyal J, et al. Gems & Gemology, 2019, (4): 660.
[3] Lee A G, Gaston G, Jennifer S, et al. Gems & Gemology, 2019, (4): 512.
[4] Aaron C P, Sudarat S, Nathan D R, et al. Gems and Gemology, 2019, (4): 536.
[5] Saeaeaw S, Renfro N D, Palke A C, et al. Gems & Gemology, 2019, 55(4): 614.