Qinghai nephrite exhibits a rich variety of colors, of which the distinctive cyan and smoky-violet colors have not yet been found in other areas. In gemstone research, a consensus that cyan of the nephrite is caused by Cr³⁺ has been basically reached. However, there is less research on the cause of smoky-violet color. Thus, the authors went into the mining area and markets to collect a large number of smoky-violet nephrite samples. Using microscope, Raman spectrometer, UV-VIS micro spectrophotometer, EPMA and inductively coupled plasma mass spectrometry (ICP-MS), the authors have detected that the smoky-violet color is not caused by the chemical elements contained in the nephrite, but by the scattering of the incident light, which causes purple or gray tones, resulting from the abounding dark minerals such as graphite.