The Dushan jades of Nanyang occur as veins in the tremolitized gabbro body. Various sorts of typical samples (white jade, green jade, white-green jade, brownish black jade) have been selected to perform polished and thin section microscopic observation, EMP, XRD and infrared spectral analysis, microhardness determination and SEM observation.The results of these studies show that Dushan jades are very peculiar in mineral composition, with "pure" anorthite and zoisite as the main minerals associated with a series of Cr bearing minerals, such as chrome-epidote, chromian muscovite margarite, chromian biotite-phlogopite, volchonskoite and chromite. Rock-forming minerals are characterized by high calcium, high aluminium and poor silicon, suggesting that Dushan jades were formed in a rather unusual geologic environment. Due to integrated control of original rocks and late-stage hydrothermal fluids, the main products are Ca-bearing aluminosilicates. With the intensification of hydrothermal metasomatism, the minerals might haev evolved in order of anorthite-zoisite, epidote-muscovite, and margarite-volchonskoite. Many minerals of Dushan jades contain chromium, which must have had much to do with the green and bright green colors of Dushan jades.