There is a national inspection on the 22nd floor of Building C of Beijing World Trade Center, which can be used to detect certificates. There is a gemstone appraisal center on the 5th floor of Peking University Geoscience Building, which can also be used for testing. Major jewelry cities generally have jewelry testing centers. The certificate issued by the test can only determine what the material of this jewelry is, whether it is natural or not, and what the composition of gold is, and it has no value. It costs tens of dollars to get a certificate, and the time is determined according to the schedule. It usually takes three working days.