The first is China Metrology Certification, or CMA for short, which is the abbreviation of China Metrology Certification when translated into English. All product quality supervision and inspection institutions and other laboratories that provide fair data to the society must obtain Chinese metrology certification, that is, CMA certification. Only testing institutions that have obtained metrological certification can engage in testing and inspection, and CMA marks are allowed to be used in inspection reports. The inspection report marked with CMA can be used for product quality evaluation, results and judicial appraisal, and has legal effect. Second, the symbol of the following units, zhongwei Jewelry and Jade Quality Testing Center, is a jewelry and jade testing and appraisal unit that has obtained the measurement certification qualification certificate of China National Certification and Accreditation Administration. The third ilac is international laboratory accreditation cooperation. ILAC-MRA is the symbol of the multilateral mutual recognition agreement of the organization, and the fourth is the certification of testing centers. The fifth is another symbol of Zhongwei Jewelry and Jade Quality Inspection Center/Beijing Zhongwei Baojingzhu Gemstone Evaluation Co., Ltd., abbreviated as ZWJC in English.