"Lemon jade" is a yellowish green opaque jade with vitreous and porcelain luster, and has dense structure. Its refractive index and Mohs' hardness is 1.53～1.55 and 4～5 respectively. Under the polarizing microscope, its structure is close to aphanitic structure. According to an analysis of Fourier transform infrared spectrum, it has characteristic absorption peak (1 537, 886, 745 cm^-1) of magnesite. X-ray diffraction analysis reveals that there is magnesite(MgCO₃) in "lemon jade". The electron microprobe analysis (EPMA) indicates that the main chemical component of the sample is MgO, with minor NiO. The well-distributed yellowish green fluorescence surface is caused by the injected glue and wax in the process of working. The "lemon jade" is a kind of nickel-bearing magnesite.