1. First look at whether the issuing institution is formal. The more authoritative jadeite appraisal certificate is NGTC/GTC/GDTC/ Jilin. NGTC, the abbreviation of "National Jewelry and Jade Quality Supervision and Inspection Center"; GTC, the abbreviation of "Guangdong Jewelry and Precious Metals Testing Center"; GDTC is the abbreviation of "Guangdong Gold and Silver Jewelry Testing Center"; GIYN is "Yunnan Jewelry and Jade Quality Supervision and Inspection Institute". Among these testing institutions, the most authoritative one is NGTC, which belongs to the Jewelry Management Center of the Ministry of Land and Resources and is the maker of China's jewelry industry standards. GTC/GDTC/ Jilin belongs to provincial units, that is, provincial jewelry and jade appraisal centers. As for smaller institutions, their authority will be slightly reduced, but as long as the testing process is standardized, it can still be used as a scientific reference.

2. Secondly, see if there are signs such as "CMA" and "CAL" on the certificate, which represent the qualification of the institution. There should also be pictures of the samples, the shape and color of the goods should be consistent with the real thing, and the certificate number and agency seal are also essential. In the signature column, the professional jewelry and jade appraiser responsible for the appraisal should have the jewelry appraisal qualification (with NGTC, GIC, GAC, FGA and other certificates).

3. Finally, only the website, contact information, code and other detailed information of the testing institution on the certificate are complete, can the authenticity be determined.