COMPARATIVE STUDY ON THE COLOR OF NATURAL EMERALD,SYNTHETIC EMERALD AND GREEN BERYL

Natural emerald，synthetic emerald and green beryl sometimes have similar appearance. Author analyses them by electron microscopy and visible light spectrometer in order to determine the difference among them in chemical com position and color indexes. The result shows that their colors are related to the concentration of trace elements, Cr and V; the color index of each one is characteristic.