Gem and jade appraisal certificate "CMA" is the English abbreviation of China Metrology Certification. It is a comprehensive certification and evaluation of the testing ability and reliability of testing institutions by the metrological administrative department of the people's government at or above the provincial level according to the provisions of the People's Republic of China (PRC) Metrology Law and the National Metrology Law.

This symbol only indicates that the organization is a unit that has passed the measurement certification review and is a necessary qualification for any unit that issues a jewelry appraisal certificate. The inspection report marked "CMA" can be used for product quality evaluation, results and judicial appraisal, and has legal effect.