Abstract: Recently,black synthetic moissanites are found in a piece of diamond jewelry consisting of black diamonds and colourless diamonds in jewelry market.The similar diamond jewelry samples should be paid attention to for domestic and international gemstone testing organizations.The black synthetic moissanites are tested systematically by using the gemmological microscope,infrared spectrometer and Raman spectrometer.The results show that the black synthetic moissanites are of rough surface,round blunt edges,growth detect and crystalline silicon inclusions.The infrared reflection spectra of the black synthetic moissanites are entirely different from that of black diamonds,as well as the Raman scattering spectra with the lack of 1 332 cm^-1 which is the characteristic peak of diamond.