Gemmological Characteristics of Grossular Jade as Jadeite Imitation

In recent jewelry market of Sihui，Guangdong Province，a new jadeite imitation appears and is sold as cabochon bracelet or necklace.According to the results of conventional tests，the refractive index of sample is about 1.70and density is about 3.32g/cm³.To make sure the mineral components，structure characteristics and trace elements，infrared spectrometer，X－ray powder diffraction spectrometer，ultraviolet－visible spectrophotometer，X－ray fluorescence spectrometer were used for further research.The X－ray diffraction patterns show that the main mineral components of samples are grossular，diopside，vesuvianite and albite.The result of X－ray fluorescence demonstrates that the main chemical compositions of the sample are Ca and Fe and it also contains a small quantity of Cr，V，Ni and Cu.The colour causing elements of samples are mainly Cr and Fe.