1. National Jewelry and Jade Quality Supervision and Inspection Center (hereinafter referred to as "National Inspection") is an inspection unit for diamond grading and jewelry and jade ornaments, and must go to Beijing or Shanghai.
2. In the local area, every provincial capital city will have a special jewelry appraisal agency. For example, in Changsha, you can go to Changsha Jewelry Testing Center.
The above are some ways to handle the national inspection certificate of jewelry, and I hope it will help you.