Un exceptionnel zircon photochrome de 9,89 carats
Féodor Blumentritt(1) & Franck Notari(1) ABSTRACT We were fortunate to observe and analyze a remarkable 9.89 ct zircon showing a strong color change from vivid orange to dark brown after longwave ultraviolet illumination (excited state). Its color comes back to vivid orange after being kept in the dark at room temperature for several months, or […]