The development and key technological improvement of synthetic diamond in China

Synthetic diamond was started in 1963 in China. The evolution data of its output and quality were presented. The output has been successively at the top of the world from 2000 until 2013 and quality has attained the advanced world level. A quality evaluation method revealing the intrinsic quality was also presented，which is the first chemical evaluation method for the absolute content determination of oxygen，nitrogen and other impurity in diamond. The content comparative analysis of representative diamond at home and abroad was made by this way. The testing results are very approached to each other. The achievement in the field of synthetic diamond in China should owe to three major technological improvements： large-sized cubic hinge press，high quality cemented carbide anvil and industrialization of powder catalyst and indirect heating. Technological characteristics and development of the three aspects were elaborated.