Excuse me, what does the certification mark on it mean? What certification bodies are they? Does it exist?

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.

The second is the symbol of the following unit, zhongwei Jewelry and Jade Quality Inspection Center, which is a jewelry and jade detection 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 this organization's multilateral mutual recognition agreement, which you have never seen at the end of TWQ.

The fourth should have something to do with the fifth, I don't know.

The fifth is another symbol of this unit, and its English abbreviation is ZWJC.