Gemmological Characteristics of Dark Green Jadeite Imitations

In recent years，the jade market are flouded with many dark green stone samples，which are sold as jadeite.In this paper，characteristics of mineral components of materials from Guangdong jade processing and wholesale distribution market were studied by means of the conventional gemmological methods，infrared spectrometer，X－ray powder diffraction spectrometer and polarizing microscope.The results indicate that the specific gravities，infrared spectra and refractive indexes of the dark green samples are similar to those of jadeite.However，their characteristics of mineral components are significantly different from jadeite，as amphibolite.According to comprehensive judgment，the four samples are jadeite imitations.At last，the authors remind inspectors to be more cautious to such samples which can not be distinguished by conventional gemmological tests and infrared spectrometer.It is an effective way of microscopic identification.