NJC was first established in 1995. Its main business involves jewellery testing, jewellery testing technology training and standardization. Since its establishment nearly 30 years ago, the company has a considerable influence in China’s jewellery industry market. At the same time, NJC has been authorized by the State Administration for Market Regulation and has become the National Jewlery Quality Inspection and Testing center(NJC). and it is work unit as secretariat of SAC/TC 256 and also technical focal point for ISO/TC 174. NJC provides companies and private clients with certifications and reports with legal validity in field of gemstone identification, diamond grading, gemstone grading, precious metal assay, plating thickness of precious metal in jewellery, nickel release and testing of harmful elements in jewellery.