Tingting Gu¹, John W Valley², Kouki Kitajima³, Michael J Spicuzza⁴, John Fournelle³, Hiroaki Ohfuji⁵, Zhenting Jiang⁶ and Wang Wuyi⁷, (1)Gemological Institute of America, Carlsbad, CA, United States, (2)Univ Wisconsin Madison, Madison, WI, United States, (3)University of Wisconsin, Madison, WI, United States, (4)University Of Wisconsin Geoscience, Madison, WI, United States, (5)Ehime University, Matsuyama, Japan, (6)Yale University, New Haven, CT, United States, (7)Gemological Institute of America, New York, United States